We ran NX4 on Unix then Linux very successfully for decades....then when the economy went to downhill and all departments were cut back our Linux support was removed and we were forced to go to windows XP 32 bit......a grand failure with bugs and system failures, with XP 64bit running much better. Whether it was because our IT department was totally unprepared to take on cad administration (we had been a self sufficient department up until that point), or some other reason, we went through more than two years of hell. Windows 7 was a huge step up as far as stability and compares to our Unix/Linux experience.
Windows XP 64bit took more than approx. 17% longer to regenerate a model than Linux on the same machine dual booted. This was verified with timed tests by both our department and our IT department. Being that our IT department required our systems to run security software and other services we really don't use (need), we just figured Linux just was running leaner because we choose not to not load unnecessary services.
All things considered....I would prefer Linux, easier to administer (no flamers or haters please, I walk in both worlds and my experiences are my own), but I find windows 7 acceptable.