Just installed Windows 7 Ultimate (x64) on my laptop. Worked very smoothly, the only thing I had to find a driver for was the display adapter (and I already knew that and had it downloaded).
In fairness, I made the decision to buy a new hard drive and keep the old one handy (and unwiped) just in case. Now I just need more RAM (it has only 2GB) so I can run XP mode. Since I have a 64-bit OS installed now, I can actually use 4GB, so it makes sense to upgrade that.
Now to install our new product on it... :)
I've been using the 64 bit version of Windows 7 on my personal desktop since it was a Beta. It is definitely Microsoft's best Windows in a long time. Of course we are talking about the people who brought us Windows ME and Windows Vista.
So in that light, I really do like Windows 7.
Yeah, I didn't have a spare 64-bit machine to run it on in beta. So I figured I'd do the laptop first for the release version. The video card isn't really up to snuff (it makes the Windows experience index 3.4 when other components range from 5.2 to 6.1), but I don't play games so I don't really give a shit...
When I build my new workstation after the first of the year, it will probably have an i7 quad core and all the trimmings. Can't afford it right now.