I've been a linux advocate for quite some time. I really dislike the Microsoft business attitude as I see it. I like open source software, I like being able to compare ideas. I have been using linux on my servers for years, and about a year ago put ubuntu linux on my laptop. A recent upgrade screwed my wireless networking up and I gave up in disgust and went back to windows temporarily. I admit, that I had forgotten how good a user experience windows actually is. Yes there are faults, but show me software that has no faults. I confess that my biggest problem with windows is Microsoft. As Kev put it 'welcome back to the world of productivity', and for desktop work (not servers) I find myself having to agree.
I guess it has the polish, responsivness and 'just works' that I didn't find with linux.
For servers though, my experience is that I wouldn't touch windows unless I was forced to by a software requirement.