I've been running my workstation on Win8 for over a month now. Really not that much different once you figure out you can use the same interface that Win7 had. There are a few differences, like where to find the start menu, etc, but nothing really that major, so I don't know what all the whining is about. To get the old interface all you have to do is run your mouse pointer up to the upper left hand side of the screen and an icon will appear for the other interface, or on the start menu click on the icon marked "Desktop". Click it and there you go, Win7 interface.
As far as using the back key on a browser goes, I've always used a mouse with a back button on it, so that part didn't bother me.
The tradeoff is that Win8 is a lot faster on any given machine than Win7. And there are some other nice features. If you run multiple monitors like I do, you get the task bar on both monitors. Lots of other neat features as you learn it, as well.