Running on a tweaked Vista for a little while now, I made the switch to Windows 7. Hearing such great things about it, despite not being a full release, I made the switch.
So far I fully plan on buying the upgrade, it doesn't cost too much and so far I am very impressed by Windows 7. Compatibility, so far, doesn't seem to be a problem and on my 1 GB ram, 1.7 GHZ PC, the OS runs very smooth.
Compared to others, I have liked Vista. I definitely had more problems with it than XP and it wasn't the fastest OS, but I always thought it was a solid OS and bashed - sometimes overboard. But with just good things being said about Windows 7, I had to give it a try.
I'll probably post later on to update my Windows 7 experience, but so far, so good!