I"d agree with the general support for the Harmonys - we use Harmony Ones for both our main systems; while the set-up is a hassle, it's workable, and making minor changes isn't too painful. The only annoyance I've had is the double-up of codes between the Apple TV and our Mac Mini, meaning the Mini switches on and is controlled whenever using the Apple TV (never managed to sort out alternative codes). Oh, given some devices now have blutooth remotes means these learning remotes cannot always replace every remote (eg, our Amazon Fire TV), so it's no longer one remote to rule them all!

The Ultimate is expensive at nearly $400 (see http://pricespy.co.nz/#rparams=ss=logitech%20harmony) - almost twice that of the One, but that is starting to get fairly old in the tooth (I think we bought our first One at least five years ago?). If I was buying today I'd probably look seriously at some of the more recent models like the Ultimate.

I would seriously avoid relying on a mobile or tablet to act as your 'smart remote'. Despite having many devices that can technically be controlled by this means (ATV, receiver, TV, Bluray...), I find I never use them as it's just a hassle and not intuitive. Also, as the post suggested above, it's fine for the individual with their phone set up that way, but it's really not a device that's easy for all to use. What happens when that particular device isn't available? Or flat? The Logitechs have base units which means they're always charged and always easy to find (unless the damn kids forget to replace them on the dock!).

Also, there's no substitute for hard buttons of a proper remote - my first 'smart' remote was full touch-screen, and it was a complete dog to operate, given the user had to check to be sure they were pressing the right buttons. The One falls naturally in the hand, and I'd know the location of all the important buttons without looking. It's always to find that important balance between hard and soft buttons, and indeed their location (something I vaguely recall reading that the Ultimate hadn't got quite right?).