They are good
We took a couple of them skiing earlier in the year and I have a few points to make...
1: If you don't like the fish-eye effect, one of the modes (can't remember which) just uses the middle of the sensor and so bypasses the fish-eye.
2: They adjust to light incredibly well, particularly darkening... going through a tunnel with it, and watching the playback we all commented "so that's what the inside looked like" - our eyes couldn't adjust quick enough, but the gopro could!
3: Using the helmet mount, you'll look like tinky-winky. That may be a good thing, depending on your personal attitude!
My only real criticism is that it isn't hugely obvious when you've started/stopped recording - especially when wearing big gloves, but with a bit of practice you get used to it.
Overall, I'd probably agree with 80%. I doubt you'd get anything better though when you consider the versatility and quality of the footage.
Also, once you've seen/used them, you notice that they're used a lot on TV... things like Top Gear and Gadget Show, among many others.