<rant> Here's my 2 cents worth. I've been working in computers professionally for 30 years. I'm a CIO now, have come up through the ranks from a junior programmer to senior software engineer, project manager, IT director, etc.
Over the years I've worked on IBM mainframes, Cray supercomputers, minicomputers, commodore 64, and PCs. I've never had as much frustration that when working with Windows. Seems that after Win 3.1, things have gradually gotten worse. It seems that about once a year I would have to just wipe out the hard drive and start all over again. This usually takes a couple of days to install windows, office, visual studio, sql server, all of the service packs, fixes, etc.
Usually it was due to some nasty registry corruption issue, sometimes it would be due to a failed install of MS Office or Visual Studio. A couple of times I got burned by installing beta s/w from MS. Win 95 beta comes to mind, as well as Access. The overall quality is pretty crappy.
About 3 years ago, I took a chance and bought the original MacBook Pro model and installed the beta version of Parallels. This worked well for me. I was still able to run windows. I need to use windows because 90% of my development is still there. Virtualization allows me to keep a good, clean sandbox version of windows. When the working copy gets hosed, I just copy the source code and databases to a new copy of the clean sandbox. The save me about 2 days of reinstalling everything.
In the mean time, I have grown to learn and appreciate the fact that It Just Works. So many times, windows would crap out due to driver issues or similar headaches, even when trying something simple.
I can also appreciate that my new machines came with iLife, and iWork is a bargain. I don't need 90% of the bloatware that comes with Office. All I need to do is a simple document or spreadsheet once in a while. Compare iWork with Office pricewise, its about 3 times the cost.
Now look at Visual Studio. The version I need is over $500. Xcode is free. Compare OmniGraffle Pro with Visio. Again, all I need are the simple features. Again the price is much more reasonable.
There are a lot of nice utilities for the Mac out there that are either free or very inexpensive. Check out Time Machine, nice.
In 3 years of owning macs, I've never had a serious issue i.e. where I had to reinstall everything or lost any files.
Now look at MS past practices. They lost their case several years ago, but still have problems. Look at the EU, they are pushing back against embedded IE and for open document formats. In my opinion, ms is the evil empire. </rant>