I only recently started using Vista on our home system, and for testing in my web development job - it's fine for general surfing, email, etc but I would not upgrade my audio and video production machines. Too many hoops to jump through, and I really don't like the constant popups, security notices, etc. Even after turning off all that, it's still a little paranoid.

I thought I was paranoid, but Vista is even more so... ;)