I just watched a side-by-side comparison here: https://www.youtube.com/watch?v=RemeuGprSq0

I have no use for actions cams and am not an expert in any way, but the quality of that $20 camera looks amazing, in some scenes it actually looks sharper and better than the GoPro that costs 5x as much.

The quality is certainly good, how's the durability? That's the reason to get an action cam, if i just want 1080p video i can use my smartphone.

I used it primarily as a travel & underwater cam. The software is pretty terrible out of the box, and I ended up having a decent # of pictures that were either never saved or "lost" from the memory card. (The card was fairly old - so this could have been an issue with the card...) Also the camera stopped working completely (as in wouldn't take any pictures, and wouldn't turn off without taking the battery out) after about two months of use.

Given it was $50, and the shots I was able to pull off the memory card were great, I am not too upset. However, caveat emptor.

Unfortunately, in that preview, the (interlaced) GoPro footage has been incorrectly processed. If you pause the video at any point, you'll see the double-imaging in the GoPro footage - an immediate sign of incorrect processing that isn't the fault of the videocamera.

This happened because the GoPro probably records interlaced footage, which didn't get properly deinterlaced by the video-creator's software. Basically, the GoPro didn't get a fair trial.

That said, the SJ4000 footage has a decent quality, and I'm all for capable competition.

Bear in mind that there are a lot of counterfeit SJ4000s out there of varying quality, some of which are sold using photos of the genuine article. At that price I wouldn't be surprised if it's a fake.

This one looks fake though. Compared to the originals: http://www.sjcam.com/3-cameras

720P MJPEG counterfeit, basically worst #808 clone in sj4000 looking case