In reply to The Lemming:
OK, going to ignore your request about GoPro only..
I've owned GoPro Hero, Hero2 and Hero3-Black.
Now use a Mobius Standard Lens (£58). I reckon at 1080P is better/as-good as Hero3 Black. I got bored with GoPro battery life and annoying menu system. I love the no nonsense simplicity of the Mobius. Not waterproof though - there is a case available. I bought camera from www.joovoo
Some Mobius footage here 1080P high bit rate (remembering this has been compressed by Vimeo):
Versus GoPro Hero3 1080P here (remembering this has been compressed by Vimeo):
That said, the GoPro Hero3-Black 2.7K/30fps footage is very very good and a real big step up from 1080P. New 4K at 30fps will be amazing I'm sure.
The white balance on the Mobius can be a bit odd sometimes when conditions change fast (like when riding downhill)