The biggest problem with 8 is that it's got all these neat new ways to do things so much quicker, but MS doesn't bother to tell you about any of them. It really is about the least discoverable OS made in the last 10 years. Sure, once you learn all the new features, you're hauling ass and doing things 10x quicker than you could before. But that first week when you don't know crap? It kinda sucks. Even though I think it's blown far out of proportion, I can kinda understand why people rage about it after their initial impressions.
And it's not like MS goes out of their way to help you out much. Their big tutorial video that shows right after you first install it is basically...
"Hi!"
"We'll teach you how to use new Windows while we set up your PC"
:video of giant cursor flying towards the corner of the screen"
"The corners do things now"!
"Okay, your PC is ready. Good luck"!
...oh yeah, that makes things so much clearer. Going to the corner of the screen brings up weird icons. Yeah. Alright. Appreciate it.