As a bit of a "power user", I find the "mac mentality" a little frustrating. They tend to hold your hand too tightly for my liking. Some programs are so "dumbed down" that it's hard to know what you're actually *doing*. Take burning CDs for example. Toast is all well and good, but sometimes I need to set options that Toast either doesn't offer--or has squirreled away somewhere out of sight for fear they might confuse users.
I installed iTunes to check out the iTunes store, and specifically told it not to play a damned thing (as much as they'd let me during the install). It set itself as my default audio player. Niiiiiice.
It's things like this that really aggrivate me as an infrequent mac-user. I get the impression apple has decided what the best way of doing something is--and want you to march in step. Think different? Riiiiight.
While windows isn't too shit hot, there is a wealth of software for the PC that is open source (or shareware) and damned good. EAC, foobar, replaygain, openoffice, mailwasher, daemon tools, avisynth, jbidwatcher and a wealth of emulators.
On the mac side I like FCP and DVD studio. iCal is a bit underpowered. Similar software might exist on the mac--maybe I need to speak with a mac "power user"...