The video quality differences are probably based on the light sources in the videos. I've noticed that my camera (Hero3 White) doesn't perform well in low light. The video I posted last night was taken during the day with a lot of light coming in from the patio blinds. That seems to be key from what I've personally experienced so far with my camera at least.
And while I can't speak for anyone else's video, mine was done in 1080p. From what I've learned about the Hero 3 series, the white is pretty much the same as the Hero2, the silver is the same as the HeroHD, and the black is superior to anything that they had out there. THe only other real differences between the series are that the 3's have built in wifi and are a bit smaller and have some improvement in the lenses to reduce the fisheye effect when compared to the 2s.
Sometime in the next week or so I'm going to try setting my camera up in one of my wolf tanks and catch them feeding on rosies from that angle.
