The problem is the context switching. Some apps full screen (even when they don't make sense or I want them part screen). Some control panel stuff in 'apps' (which requires full screen); some still in the old control panel. Some in both.
Somewhere along the way someone started thinking the whole 'single task at a time [or at most two]' was a Good Thing - but then someone else said that we can't do that, and what we got was the ugly bastard child of both.
I've stopped booting Windows, haven't done so even for gaming in a couple of months now. It's just too annoying at 8.x.
edit: before someone calls me on it, why no I did not read the article - I've since gone back and done so, and it sounds like they'll be offering windowed mode for metro apps as well.
So I take it back, this has the potential to make it far less annoying (if they consistently make it available for all metro apps).