the new lumia 920 is STELLAR. I just upgraded from the lumia 900, and Windows phone just gets better and better. I've been all over the place with phones ever since I got my first one, having used pretty much everything you can think of. I REALLY liked Symbian OS, even though it wasnt received well by most people. I personally like it most of all phone OS's still, to this day because it is the most involved mobile OS....allowing me complete control over everything the phone is capable of. It's very similar to a computer, in that I can zip files, change image formats from one to another, and many other things that other phones can't do.
Back on track though, windows phone has picked up on the things that other phones arent nearly as adept at. It's very user-friendly..and everything you could ever want is right at your fingertips when it comes to social networking. You don't need to download apps, everything is simply integrated. When you pull up a contact in your phonebook...it's all simply right there. All of their facebook images, their wall, everything. The lumia is also SO fluid, with no holdups. Everything just works like you would expect.
If i transfer away from windows phone, it will only be back to Symbian. And the first phone I will go to will be the Nokia Pureview 808. With a 41-megapixel camera, plus the latest Symbian Belle with all of the newest features, it's simply the phone to end all phones. Look it up...it's simply amazing. It's what every other phone should aspire to become.