Went from Mac (grew up with them) to PC in 2007 or so, back to Mac (2012 iMac 27" with i7, GTX 680MX, 1TB "Fusion" Drive...what a silly name). Virtualise into W7 if I need to, reboot to W7 for gaming (people can make whatever excuses they want, Mac OS is still a poor choice for gaming).
Dislike MS with a passion, not really that I'm a Mac fanboy - as soon as Apple starts making crap machines and software I'll switch.
As for moving back to Windows, financially it's a bit of a jumble - the iMac will have a far higher resell value than the PC in the years to come (and will sell well now), yet the custom built PC will be cheaper now. So you have to be the judge when it comes to the usual factors: which platform you prefer, whether you'd miss one if you dropped it, which offers the most benefits etc.
Just to offer another perspective in addition to Amp34's, I simply find using Windows a hugely frustrating experience. To me, it feels like they've gone out of their way to make things more difficult. Why is it like that for me? Because I'm not used to it, and because I just don't like it as much. It's a case of personal preference.
That one hasn't been the case for a long time, I've been right clicking (well, two finger tapping if I'm using the trackpad) for many years now