I've had my Nokia 928 for about 6 weeks now. Like poster 300bps above, my previous 3 phones were all iPhones (we're like .. phone twins or something)
Overall, I like both the device and the OS. So far any nits I have are minor -- Only one volume setting for all the apps, touch screen is overly sensitive, polymer case is too slippery.
So far, the WP app store has had the applications I care most about. And since you can write apps in C#, it's more approachable to write for.