I think most of the problems are if one upgrades. I did a clean install and prefer using win 7. It is quick and stable. The drivers are freely available on the net so they are not a problem. If your software is vista compatible you should not have a problem with it. Win 7 definately run better then vista.
Have to agree there, although upgrade-installs still seem to be less problematic this time round than ever before. Simply put, a clean install (just make sure you get all your hardware drivers together before upgrading) give a pretty smooth finish.
Personally, I liked Vista, but since installing Win7 (been using x64 install since RC1), have never looked back... been a very good experience :) For those who skipped Vista and are coming from XP, it will be a little bit of a learning curve, but given that things are much more logically laid out than XP ever was, and is much more intuitive, is worth the move.