mikerussellnz: The vraptor isn't usually an option as it's really a 3.5 inch drive as it requires the large heatsink around it.  So it is not suitable for laptops at all. 

I have a momentus xt 500gb in my macbook pro and it seems a decent step up from a HDD, I was upgrading from a 5400rpm drive and although I wouldn't say the XT is near to an SSD (I haven't used a SSD).  After it has learned things,  boot time from pressing the power button to desktop in 20 seconds, safari opens almost instantly, photoshop loads in 1/3rd the time of the old HDD.  

You have to remember though that it's 4gb SSD part is a limited resource and it needs to learn what you do commonly to populate it.  So in a lot of benchmarks like random read etc, it will act like a standard 7200rpm disk.

I also don't know how much you have to do to thrash out your data from the SSD part, but I gather dual booting would negatively effect the caching ability.

There was no way I was going to carry an extra drive around everywhere and a SSD large enough was not in my budget.  I needed a bigger HDD and the XT has the space and the price was reasonable.