I never understand what Windows people were using when they say things like that… While my Windows 7 installation runs for days and days and days without a problem. Previous versions there were occasional issues, but realistically there were almost never any real problems after 95, 98… I’ve been running Gnome on Arch Linux as well, which stays up unless I mess it up. And there are virtually no viruses really on any system currently available, unless you install it unwittingly. I’ve had OS X installed on this system as well, but I won’t judge the system based on my Hackintosh.
However when I was forced to work on OS X at my previous job, I had to constantly deal with FCP randomly disappearing into thin air with not even a warning message. There were so many situations where I found myself just staring at beach balls, it was ridiculous. Also, OS X just looks awful to me. Granted, Expose and multiple desktops and all that stuff are nice features… but they can be brought to Windows.