I've been using Nokia Lumia 800 for some time now, and while some aspects of the product are very polished, my overall opinion is negative.
- some tiles are animated, some not - pretty distracting experience.
- while the interface is responsive, you still need to do several taps and slides to get a result you can set a single tap under an Android or iPhone.
- 50k apps in the market if neither can do stuff I need.
- no Google apps I need - sorry, Nokia, your phone needs to be able to join existing ecosystem.
- battery - ye gods, hopefully those of you who purchase Nokia Lumia 900 do not experience the issues we have in EU with Nokia Lumia 800. In short, it's buggy, unpredictable, goes haywire in areas with worse coverage and generally tends to suddenly expire on you quickly. A show stopper.
- no easy way to access file system.
- display which simply fails in sunlight.
- limited customization.
Apart from battery issues, it's a fine phone, but compared to my HTC Desire with MildWild... it just does not come close. Yes, my HTC Desire may not perform as quick in 'Smoked' tests, but it does what I need, including playing Angry Birds for free.