I installed Win 7 on my laptop and workstation this week and both went without a hitch and am really loving the new OS now!
If I had to gripe about anything, the only thing (so far) I would gripe about is the number of automatic updates that are required. Its not a big thing as I had it set to download and install automatically so it just ran in the background.
Th UI is so much better than Vista, much more logical and usable.
I did a fresh install on both machines and I don't think it took longer than 15 minutes each from inserting the DVD to logging in for the first time. It's taken a bit longer to get all the other apps installed and configured though. Was suprised that the only driver I cannot find a working version of is the one for my in-built Teac CA200 13-in-1 media card reader. The drives still work, it just doesn't show the drive icons in My Coputer (although they are listed in Disk Management).
My graphics card, all-in-one printer, sound, Wacom tablet etc all worked first time.
The OS is pretty fast too, certainly faster that Vista in my experience.
Must say that so far I am mightly impressed with Windows 7 thus far.