I've been using Windows 8 for a little while now, and really I haven't had many issues other than learning the hot keys/charms and a few program incompatibilities / workarounds.
For example, I had to install a workaround with Windows Live to get Dark Souls to run via Steam, but it runs just fine now with no performance degradation (or noticeable increase).
The hardest part for me was getting used to using the keyboard a lot more, as a non-touch interface requires the use of hot keys a lot more rather than the mouse.
Once you get used to them though, they're actually pretty convenient.
As far as the metro ui, it isn't necessarily intuitive, but the more you use it the more you get used to it. It actually is easier for several things after a while.
The biggest thing I've seen is that fuss over the start button being gone.
It was hard to adjust to at first, but if you press Windows key + Q, there are all the same features, and the desktop remains less cluttered.
From what I've seen, it's just getting used to the new OS (much like the changes from XP to Vista, albeit those were more subtle, and well... Vista).
I think Windows 8 is a good choice if you plan on buying a Windows 8 Tablet or Phone due to the Windows Live account integration, but time will tell how useful that'll end up being.
BLUF: Stick with what you're comfortable with--they both work well.
Personally, I think Windows 7 is better for a desktop environment without touch screens, but Windows 8 does feel more responsive and doesn't have any real issues in the desktop (except the learning curve and using the keyboard a bit more--both generally negligible).