I bought an HD2 because I hadn't bought a phone in a while on contract so I was eligible for an upgrade and figured, eh, 200$, if I don't like it I'll sell it on craigslist for 400$ and make a 200$ profit. This isn't really a review because I don't have any experience writing reviews, it's merely my response to the device after playing with it for a few days.
The Good: The phone itself is gorgeous, hands down the most aesthetically pleasing piece of technology I have ever seen. Also it's been a good experience for me since I don't really have any knowledge about Windows Mobile at all. Watching videos on it is a better experience than on the N900 but that's what the phone is marketed to do. Also it feels and looks nicer in my fitted pants than my N900.
However after spending a couple days with it as my primary phone, I just can't live without certain features of my N900. I had no idea how much I relied on the FM Transmitter, the Qwerty Keyboard, facebook conversations plugin, the excellent browser (The HD2s is up there as far as mobile devices go, but it doesn't top the king! Hint: The king is the N900!) A big thing for me is that the music player in the N900 handles my 1500 song music flawlessly and the HD2 takes 10-15 seconds every time you open the music player to load all the file names into RAM, even skipping a song theres a second or two wait before the music starts.
All in all, a gorgeous device to play with that gets the job done, but it doesn't top the ultra functionality of the N900. At least with both I can have the pretty one and the smart one ;P
Now if only someone would take both of those strengths and turn it into a phone. (A pretty nice compromise of both would be the Droid I'd say)
I haven't gotten into flashing roms yet because all the ones out are kind of still in beta as the device is less than a week old (The tmobile us one has different amounts of ram and rom than the european version) but I suppose I'll get around to that eventually.
If Android does get ported to the HD2 -- and I'd trust XDA much more than some random guy at a tmobile kiosk -- it'd be a pretty big day for me.
If anyone has any questions about the HD2 I'd be glad to answer them, like I said though I'm not an extremely advanced windows mobile user. Flashing roms is something I'm comfortable doing but I've never touched the registry or anything like that.