I am and have been a converted Windows user to Mac, in the past 2+ years. I still however of course use Windows because of of work, applications, job requirements, and of course Games. I use Windows in a virtual environment, and I use Boot camp frequently. SP1 was an unbelievably simple install. I have used Windows going back to 3.0 and of all major Windows installs I can think of, this was almost as simple as a Windows update, barring a little extra time of course.
So far, excellent roll up pack, performance improvements noticeable, and no software, hardware conflicts to speak of. This is the way it should be, and hey, it's Microsoft !!!