Sony Action Cam Video is (IMHO):
1. Wider at 170FOV
2. Less noise
3. Less fisheye
4. Greater light sensitivity in low light
5. More acurate AWB IMO
6. More natural color overall
7. More dynamic range

Sounds like the Sony Action Cam is the clear winner here?

These differences are not as dramatic as the differences between GoPro Hero 1 and Hero2 under low light, but I believe the Sony is the winner in terms of video quality under extreme low light condition.

However...



Sony Action Cam Cons:


1. *This was a user error. "Hold" switch is for the on/off button. I thought it was for the lid. I would have broken the cam if I kept pressing hard on the button while "Hold" is on :) (Originally wrote) The record button is very tough to push. I had to push the button hard and many time to get it going. I am not sure if I can push it correctly to record while diving.
2. The sony cam is bit harder to setup. Once the cam is inside the case, there is no way to change settings unless I have the Wifi version with phones or tablets. I plan to use this camera underwater, so I cannot change any settings like switching resolution, FOV, or FPS while inside the case where GoPro can easily do.
3. No flat lens for underwater yet.
4. The GoPro protective case is far simpler and easier to take care of.
5. No LCD for live view that can be taken underwater, and no battery pack to extend the battery life.
6. The standard tripod mount is nice, but I cannot tilt the case like GoPro mount.
7. This is OK, but it records 60FPS and 120FPS at 30FPS in MP4. I just have to get used to it.
8. The bottom of Sony cam is not flat, so it cannot stand on its own without the case!!!
9. No 960P mode, which I believe is sometimes useful in GoPro Hero 2 with 48FPS.