For a while I have flirted with Windows 7 and Fedora 13. I spent in total 4 months on these two OSes combined. Before I used almost exclusively CentOS 5 on my desktop. And I have come back to CentOS.
The question is why? And to me the answer is clear. I feel at home on CentOS. It is not fancy, it is not up to date with the latest releases of applications like OpenOffice and the software repository is quite limited. But it works fine. Moreover it is stable as a rock. I do not mean this in the sense of crashing but in the sense of keeping your configuration working. Fedora needs an update every 6 months. After the upgrade it needs work. I always have the feeling that I waste my time to tweak a Fedora machine to my liking since it will be gone / changed in 6 months again. Moreover my battery was draining quite quickly under Fedora.
Windows 7 is a problem because it does not offer working sound support for my good ol’ Thinkpad Z60m. Moreover it is unreliable with auto suspend. It sometimes works and sometimes it does not. Try to debug that on Windows. Good luck!
On CentOS everything just works and I can easily add the missing pieces like tpb (thinkpad button support). It suspends and the battery life is great. Everything works again as it should.
Red Hat is currently running the RHEL6 beta program. Beta 2 just came out and I am looking forward to see the final version as CentOS 6. It is scheduled for the end of the year.