I've wanted to switch to a Mac for years, but since AutoDesk gave up on writing AutoCad, Inventor, 3DStudioMax, etc for Mac many years ago (insufficient demand at the time), I've been stuck in PC-land.
Then one day, the sky cracked and split in two, and...
Mac: The simple stuff, mail, calendar, web browsing, itunes, etc... runs everything smoother, prettier, and just plain old more enjoyable than windoze.
Parallels: Low priority Win stuff like playing .wmv video, .asp web stuff, accessing MS Notes & Journal docs, (I came from a (an admittedly missed) Tablet PC & all my vector sketches are stuck there), and my nice shiney HP Print/Scan/Copier which strangely can't be made to work in OSX.
Boot Camp: High thread priority heavies:
http://usa.autodesk.com, plus Sony Video camera (which also can't be made to work in OSX)
16g iPhone: Mobile backup of design archive
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Anyone who doesn't install drivers or software updates is either not using their system for anything more than a web browser, or has a highly selective memory.