This is my personal experience anyway. All day at work on Vista, crashing, stuttering, awful. Mac OS X at home.
If you already use (and are happy with) Linux, you probably won't gain much from a switch to Mac. I never wish I was on windows. I don't even have it installed in VMWare.
Our experiences are our own though. Hasn't this conversation been done to death?
outside of driver problems, which can happen on any machine and why you should get good hardware - and badly developed 3rd party apps that you shouldn't run anyway - windows has been pretty stable since win2000. not as stable as my freebsd boxes, but considering how much work i do - very stable. my desktop reboots on tuesday nights for windows updates and thats about it. all my windows 2008 machines are doing fine too, just like my ubuntu servers.
vista crashing, stutering, awful ... i read these but i have a suspicion your all exagerrating
at any rate, took me less time than tweaking a powerbook.
Now get off my lawn!