Considering that the regular desktop UI is a hot-key press away from the Metro-UI load screen, the fact that the auto-load into desktop UI is easily scripted, (and the fact that my computer runs 24-7 so the boot behavior matters to me not at all), I am ignoring all the complainers.
Windows users that are not trolling every Win 8 article with predictions of doom care about 3 things in our OS.
1) stability
2) efficiency
3) compatibility.
The first two have already been demonstrated by Win 8 - I am abig fan of my OS and software getting the most out of my hardware - the only thing that really matters really. Afterall, I'm using my PC to run software - not to stare at the desktop or getting warm fuzzies about how my desktop is arranged (in fact, its empty - quick launch bar all the way, which is metro-UI lite IMO anyway).
The one remaining concern is software compatibility, especially older software - that I've heard little about. Not too worried about it, but still going to wait and see before pulling the trigger.