Re: Weird, isn't it.....
As someone who ended up with WP7.5 more-or-less by a mistake - somewhat fuelled by a desire to have as many different environments to hand - I'm lucky enough to have an evidence based opinion. I have ios / bb / android / maemo devices.
WP feels completely different, it's UI is simple, but very alive, something that none of the others seem to manage. ios feels dull and passive in comparison. I very much like the 'live' tiles, photos changing, information, tweets, status etc. I like the integration of apps (and dammit, I like the choice of apps too, only one I'm missing is words with friends - but all the ones I use are there - evernote, mapping - lots - vnc, ssh, running stuff, internet radio, astronomy apps, etc.). Next time I'm looking for a pad, Surface (or whatever) will be a true contender.
Can't see me moving away from linux desktops though.