Been shopping a bunch for this (and despite the fact that my computer has crashed twice now while taking notes), here are the conclusions from reading Amazon reviews and Cnet. There doesn't seem to be a good source of action cam reviews:
- GoPro Hero Black 3. Despite the names, the Black, Silver and White are different cameras. The Black is state of the art but Amazon reviews show that the batteries really don't last, the accessories cost a lot and there are plenty of firmware problems. It does 1440p and the image quality is terrific
- GoPro Hero Silver 3. This seems like the more reliable one at 1080p
- Sony HDR-AS30V. Cheaper and it just started shipping, but better initial reviews. The later reviews for the HDR-AS15 have actualy been pretty good. The AS30V has the same camera as the AS15 but the changes are a lighter housing (16 feet vs 196 feet of water), and the addition of wifi, so you can see what it is doing. The main complaint is the mount that comes with it aren't that good. You have to get a $18 head mount
- Drift Ghost. Not very good reviews on firmware issues. Sigh.
The conclusion is to wait to see how the HDR-AS30V does as more people use it and then if it works well, get that, otherwise get the Hero Silver 3.