What I hate about the HD2:
1- Screen bugs. You must rely on your luck to get a good working screen
2- Voicecall quality: for some people it's acceptable but for too many others, the quality is one of the worst you can get for a 1000$ phone. Noise, crackle, distortion etc..
3- SMS loading time is miserable. HTC still is not aware of the problem or they are ignoring us because they know that their software code is buggy and needs recoding
4- Some if not most HTC devices have some hardware flaw like screen not evenly aligned with the frame that puts some question marks whether if it's going to put us into trouble in the future or not ie: top notch ( can leak water, dust, backlight, whatsoever ) or something like that
http://forum.xda-developers.com/showpost.php?p=5176174&postcount=94
5- Mediocre back speaker performance. And when it rings, it really feels like a cheap phone.
6- loose keypad. That's not really a problem but sometimes it's annoying, it also feels cheap in hand although the build quality is almost excellent.
7- Poor battery life, I mean really poor. If I forget to charge it at night, forget about calling me the next day.
8- Very sharp lens frame. That's not a big deal if you keep your device in its case but if not, beware, this thing can scratch anything it touches.
That's for me, you must also note that what I wrote is subjective and based on a comparison with my old XDA and HTC devices.
Hope that clears up things.