I've used both Windows machines and Macs for many, many years. I always prefer Macs. I use PC's only when I have to because of application requirements. I have 3 macs at home, I've used many Macs over the years at work, as well as PC's. Macs are a hellof more enjoyable to use, are way more stable than windows machines. I think they always have been, and this is more so now with OS X. It is hands down the best, most stable OS i've used.
Until MicroSoft drops their backwards compatibility requirments, Windows will never be a well designed OS. Backwards compatibility is just to restrictive to allow good design. In my opinion, Apple has the better solution: Building a completely new OS, and emulating OS 9 for running old applciations.
I don't have experience with the new Intel powered Macs, my newest is a 17 in PowerBook G4.
I do own Virtual PC, but it is quite slow/weak. Microsoft Office for Mac is better than Office for PC, however.
I think the only downside of macs is the cost premium. But the quality of the Hardware, OS, and software justifies the higher cost for serious users. My time is worth too much to muck around with Windows configurations all of the time.
Hope this helps,
Daniel