I'm not going to weigh in on the argument since it is like discussing religion or politics. Everyone has an agenda and wants validation of their ideals and followers.
Anyway, I've not heard of any serious problems with Win7 64-bit. All of the Vista 64 drivers should work.
I am excited to continue playing with some of the Linux distros, but until I get some more powerful machines, I'll have to play the dual-boot game since VirtualBox and VirtualPC works best on machines with multiple CPU cores and lots of memory.
The Apple OS is just a Apple'd Linux distro and there are ways to make Linux more OSX like and ways to make OSX run on non-Apple hardware.