Heres what I think. Others may not agree but thats the way it goes :)
NOTE: This "Blog" or whatever you want to call it is for you guys, its a mix of my OWN opinion and FACTS about different mobile OS's. I am not a "Tech Writer" Its just information from my experience for you all to read.
INDEX:
1. My History
2. Hardware
3. Features
4. Downsides
5. App Stores
6. My recommendation
7. A few more tips on selecting a phone
8. Video Demos.
This is not quite finished so bear with me :) I've not done this before lol
The purpose of this spiel is to make it easier for people who don't have the time or money to waste trying them all out to find what is best for YOU, It is hugely a personal preference at the end of the day and there will always be Apple Fanboys as well as Android Fanboys but the choice is up to you.
If you look through the blog, I will place videos of samples, demos etc... to make it easier for you.
Remember the main thing you need to decide on is the Operating System NOT the device, once you know what you want to run the device just comes down to the money you want to spend.
Firstly a little bit of background, My first "Smart" device was a Nokia N900 as far as i remember ('twas a long time ago), Which was a ver powerful phone buy the way.. From there I've had the following devices.
In Apple... iPhone 3GS (x2), iPhone 4S
In Android... HTC Desire (x2), HTC Desire HD, Samsung Galaxy S2 (x2), Samsung Nexus, Nexus S, HTC HD2 (Android and Windows), HTC Sensation (x2)
In Windows Mobile... (which is different to Windows Phone 7)... HTC HD2, I'm not going to get into Windows Mobile because it doesn't come out on anything anymore. its "expired" lol
In Windows Phone 7... HTC 7 Trophy, HTC HD7, Samsung Focus, HTC HD2
So now that's out of the way you know i have some experience in the field. My favourite is Android and you will find out why but all of them have there ups and downs, Yes even iPhone or iOS has its ups ;)
I am also a "XDA Recognized Developer" for Android over at xdadevelopers.com which was no easy feet. I Started developing the Android OS from the HTC Desire not knowing allot up to building from the source code and porting AOSP to other devices.
Lastly i want to get this in a couple of times... YOUTUBE IS YOUR BEST FRIEND WHEN YOU WANT TO SEE WHAT A PHONE CAN DO, They are ALL on there, so "Youtube it"
SO, lets get to it.
Lets start with Hardware
Devices that have Android installed are pretty much limitless, so you can buy something really cheap and nasty or you can get something that far exceeds any other devices specs across any platform. So you can go buy a Vodafone 845 for $99 or something and its just impossible to use really, or you can buy a Samsung Galaxy S2 for about $720 from a reliable importer shop in NZ which is far better hardware wise than the latest iPhone (in most areas).
With Android devices because of the variety you need to make sure you get one compatible with your provider (Telecom XT, 2Degrees, Vodafone etc..) but most of the latest ones will support any (Quad band 3G devices, Even 4G now which is not available in NZ yet)
Now if you do buy a cheap "nasty" Android phone, they are NOT nice and they will put you off Android because they just dont live up to the standard that Android is supposed to run at. Generally if you get one with at LEAST a 1Ghz CPU and 512Mb of RAM you will get something good enough. Although most of the new ones are dual core and perform very well. You do pay a premium but its worth it.
Apple devices.. well theres only one, the all famous iPhone. ALL iPhones are over priced... Really they are not ALL over priced but i feel personally that if im going to pay $1100 upwards for a phone i want one thats nicer to hold, has a bigger screen etc.. but thats just me. The latest iPhone 4S comes with iOS 5.0 Which is actually pretty nice and easy to use, and runs really fast.
The issue is the last 2 devices still have a sharp edged 3.5" screen with glass on the front and back and If you drop it your done for. In the hand its pretty bad to hold unless you get a good plastic case. I wouldnt say its a "Bad design" but i think in a rush to release a better phone from the iPhone 4 the rushed it a little to much, but is still much better than the first iPhone 4.
Remeber if buying a new iPhone and its between the iPhone 4 and the iPhone 4S, i cant stress this enough, the 4S is alot better than the 4, purely because of the dual core CPU and the much better camera.
ALL iPhones bought in NZ and most out of NZ will work on ANY NZ provider.
Now dont get me wrong, I DO think the latest iPhone 4S is a good phone. I think if you want something simple and easy to use they are great and infact its pretty hard to get an Android device to run as fluid as the latest iPhone will.
With iPhones or iOS, because its so locked down there generally are less "issues" and the general iPhone user will go through its life without having any issues, sure you might get a dud update every now and then but Apple generally fix it pretty quickly.
One thing to remember with iPhones is the battery is part of the phone, it cant be removed by your average user and generally requires being sent it to a repairer or Apple store. A lot of users will never have to change the battery but it is a point to remember as the iPhone battery isnt amazing compared to what is coming out now on other platforms.
Windows phone 7 devices are a different breed.. You can still get quite a few different types now, an what Microsoft have done is set a "Minimum System Requirements" level which is a 1Ghz CPU, a 720p video camera and a Camera hard button (among other things) what this does is give you a uniform experience in speed and smoothness regardless of which one you buy. Although now there are new dual core devices coming soon the old ones are still very smooth and fluid and they all have a decent camera, still having the option to upgrade and get one with a better camera, or a bigger screen etc...
Now on to Features
Android is by far the most feature rich OS, you can do things like change the onscreen keyboard, change launchers, Use apps to automate things like GPS and Syncing emails etc, You can use "Widgets" like calendar, tasks, Facebook widgets etc to see everything you want without having to open an app.
You usually have removable storage with most devices, a big one is having Flash support in the web browser which means you can watch videos on the TVNZ site or any site without having to open a video player, nether iOS or WP7 (Windows Phone 7) support Flash properly.
By far the biggest feature is the ability to install different custom "ROMs" a ROM is Operating System made by a developer like myself and tones of others on XDA. This give you the ability to decide what you want.. Don't like HTC Sense? Don't use it, install CM7 or something instead.
Also with Android comes free PROPER turn by turn navigation on every Android device so you don't have to spend $99 buying an app that doesn't do as good a job on iOS and WP7 doesn't have any good navigation at all at the moment.
What's that you say? "But iPhone 4S has Siri!" who cares! Android has Vlingo which does just as good a job ;)
While im talking about iPhones, when you have a MacBook or a Mac computer they do sync very well with each other and don't usually have issues with that, On the other hand Android Syncs very well with Macs also.
Now iPhones and WP7 devices do have features also, don't get me wrong, Its just Android can do everything they can out of the box. However if your really into music, In my opinion iPhone is by far the best for listening to music, they are basically an iPod touch but with a phone inside.
Another feature of WP7 is its awesome people hub and messaging system, its all integrated into one place and works VERY well. In the messaging hub otherwise known as SMS app you can txt, facebook chat, use Windows Messenger networks, just about anything. See video demo below
Downsides
Now all models have downsides, for example iPhones inability to remove the battery, or the lack of any kind of good navigation on WP7, with Android cheaper models can feel slow or "laggy" that's because they don't have the power to properly support Android.
You WILL come across issues when hacking up your Android device and that comes down to user error most of the time unless you are installing some fresh ROM that is still in Alpha stage, saying that iPhone's "Jailbreaking" process can cause huge issues also, the thing is its easier to fix on Android than it is on iOS.
So when thinking about it if you willing to fork out $1200 for the latest iPhone, for less money you can get a far better phone on Android, WP7 is still very young and while it is still nice to use its very simple and lack luster at the moment, but if you just want a nice fluid device with a good camera and not much money its a good choice.
With Android the experience is VERY device specific so if you dont get the right one you probably wont like it as much, but i will point out some good ones to get in different price brackets as of now later on. Another thing with Android is updates can take a while to come round by them selves so unless you "ROOT" your device and install it manually you may wait a while for what you want.
App Stores
Android's Market is packed full of awesome apps and most of the good ones are free, Apples App Store is also packed full of apps but most of the good ones cost money and most of the free ones a just crappy games and useless fart machines. Windows Phone 7 apps store? what apps store lol, as i said before its still VERY young but it is growing pretty fast, but you will come across something your friend has with Android or iOS and get pissed off cause you cant have it!
My recommendation
If you have everything Apple in your home already AND you love them, then you should probably get an iPhone. Reason being is most of the die hard Apple fans will love the iPhone regardless if you can take the battery out or one of the updates is crap, because it is still a good phone, it still works and although it may be a little over priced, if you love Apple chances are you will love the iPhone.
iPhones are VERY easy to use for most people and you will pick it up alot quicker than Android. It can take sometime to learn everything you Android Device can do with all the latest versions, especially when you get one with HTC Sense (Which is good but adds alot more to it)
If you are a "Power User" and just want to constantly fidle with stuff then Android is for you, Im constantly updating and hacking up my phones, so much i cant even really use them to there full potential because i have to "Full Wipe" them daily lol. It becomes a habit when you turn into a "Android Power User" and can take ALOT of your time. How ever it does come with reward if you do want to do it. Its not that you have to fiddle with Android to make it cool, but you can make it so much better and more personal to you by doing so.
Windows Phone 7 i would recommend mostly to the "All in one place" people. Its an excellent social networking device, the people hub works really well as does the messaging hub and it all just works really well together, once it gets proper navigation and all the other features it WILL get eventually it will be a fantastic OS
A few more tips on selecting a phone:
iPhones >>
If your going to go with iPhone and plan to buy a new one, it really is worth getting the latest iPhone 4S if you are choosing between that and the 4. BUT either way if you really cant afford the 4S then the iPhone 4 willl still provide you with a smooth user experience and the main thing you will miss out on is the better camera.
Android >>
With Android, If you want a really nice experience, you do really need to get a top end device to be able to compare it to the smoothness and quality of the iPhone 4S.
However if you want a smart phone but cant afford a really nice one, there are many that will do the job fine. If your on a low budget, i think (IMO) the best thing to do is go second hand on trademe or something, you can get some really good bargins.. example just today i bought a Nexus S for $450 and it was never used, the Nexus S now with ICS Android 4.0 competes really well with high end devices and will give you a nice smooth Android experience. Other devices that still hold up well (2nd hand im talking) are the HTC Desire, Desire HD, Nexus one, Samsung Galaxy S (Which you can now get for $499 NEW) Things like that, Big brands... Ive not tried the cheaper branded phones but they are cheap and some people say they are good value for the money.
YOUTUBE << Is your best friend when comparing phones! So use it! Pretty much EVERY phone is on youtube with a demo and you can get a good idea of how its going to run ;)
Windows Phone 7 >>
You are pretty safe with any Windows Phone 7 mobile. As i said before they have a minimum requirement which keeps it simple, so its really a case of more money = more features ;)
Buying on a budget
When your shopping on a budget it pays to look first at places like "Expert Infotech" on the North Shore or even "Clove" in the UK, it may surprise you what you can get really cheap. For example you can get a low end HTC Wildfire S for $316 at the moment NEW, not the best device but really good value for that amount. Or even a step up to the Desire S for less than $500, great phone for the money. I think you can even get a Samsung Galaxy S NEW for less than $500 now.
When talking REAL cheap, im not to sure i need some of your opinions on those models, personally i think when going real cheap getting something with a decent screen is important seeing as the keyboard is on it ;) so remember to get CAPACITIVE touch screen if you can.
Video Demos
These should give you a good comparison of all of the systems.
iPhone 4S Review, The latest iPhone out
HTC Sensation XL Review, This is a Mid/High end Device running Android with HTC Sense
Samsung Galaxy Nexus Review, The latest Android Device running Android 4.0
And just to compare this is a Google Nexus S running the same OS as above on the Galaxy Nexus but the handset is only about $499 new in NZ from Vodafone
HTC Titan Review, This is one of the latest Windows Phone 7 devices, it has a HUGE 4.7" Screen which is obviously 2 big for some but still the experience is the same just larger
Here is a demo of the latest iPhone and the latest Android device comparing internet browsers
So in the end it does still come down to your own personal preference but hopefully this has made it easier ;)