I'm a iPhone user, but looking to move back to Windows world. I played with a Lumia at the AT&T store, and I'm impressed. It wasn't too big, which was a concern. But learning the "Windows way" of doing things will take time. Got a couple years of iPhone habits to break.

Camera button, kinda cool, but not enough to wow me.
Cyan texture, ok. Might like it to be a little soft and tacky for setting it on tables, etc.
Windows - fast. Quick smooth transitions. Fast downloads.

Think I might buy one soon -- 4 months or so.