I think I'll just tell everyone what I think about my Lumia 900 here...
Well, coming from an aging Galaxy S, it sure beats having to deal with lag, frequent browser crashes with Opera Mobile (the default Android browser is too creaky), slowness, no camera flash, the laundry list of faults I find with my out-of-date phone... Well, I ended up signing up for a 2-year contract and a Lumia 900, seeing as I'm not going for iOS, don't have much cash for just a phone, and was fed up with Android.
Well, it's certainly one hefty but durable phone, and it's still carry-able. Things are just oh-so-snappy and I don't think I've ever seen a messed-up site ever since switching phones. The only gripe I have with my current phone is that the glass screen is a fingerprint magnet, which isn't much of a bother, seeing as I can clean it easily.
And I bought it even knowing that it'll only get WP7.8 anyway, since if we wait, wait, and wait, it'd be an endless cycle, and I cannot not have a working phone.