Just did a clean install of Win7 yesterday. It's even better than the upgrade. Screen fonts are so much easier to see. I backed up well, but it turns out the clean install preserved all my data directories, such as music, audiobooks, personal files. All I had to reinstall was software. I had to reinstall HP Update from the HP Win7 64-bit web page, but running HP UPdate found nothing missing. I have a Touchsmart, and the touchscreen works fine with Win 7. I can't get over how clean, fast, and convenient Win 7 is.
I have to use QuickBooks and WordPerfect for workamping, and both installed better and faster with Win7 than they did with Vista. Intuit tried to tell me I need to buy QB 2010. Every time I reinstall and have to reregister QB, they waste a bunch of time trying to sell me stuff like payroll services. But I digress. QB 2008 is working just fine. The QB updates installed faster than ever.
I think the new video driver is better, and music is excellent. Then, again, this HP Touchsmart probably has especially good speakers or something. Media Player does a nice job with DVD movies. I'm leaving off all the stuff that came with the HP. So far Win7 is doing it all. Haven't written a CD or DVD yet.
--pat