Me personally, I much prefer W7 to XP. I was a die-hard fan of XP but managed to get hold of a beta release of W7 prior to launch, and it shocked me how much things had come along - I mean I'd never have considered installing Windows and having most of my hardware drivers sorted for me at the point of install. Its certainly not something you get with XP, unless you use nLite of course.
I'm also a big Linux fan, so I'm always running that as well. If I'm not gaming I'm using Linux. We have W7 on every computer in our house now, and from my perspective its much more manageable and stable than XP.
I can't say I've really had any problems with W7 at all to be honest; Maybe I'm lucky, but we run it on a range of hardware, new and older, and it seems fine with it all.