I very nearly bought a GoPro, but while reviewing YouTube vids I came across a comparison between one of these and a GoPro Hero 3+ Black edition (Look out for Techmoan). The video quality of this camera is excellent. YouTube doesn't do it any justice what-so-ever. I'm very very impressed with this camera and more impressed by the fact it's £100 cheaper than its equivalent... the Hero 3+ black edition. Admittedly I haven't been able to make a direct comparison of image quality, but it's hard to see (I doubt it would be even possible to see) how the GoPro could be any better.
The battery lasts for around around 3 to 4 hours depending on different factors... image quality, GPS on or off, WiFi on or off etc. It's possible to buy a spare battery and change it on the move. Charging via USB from the computer takes around 4 hours. It takes half that time with the optional charger. I would also highly recommend buying a decent memory card for it. Like the GoPro it doesn't come supplied with a card, so make sure you purchase one at the same time. I bought a 64GB ScanDisk micro SDXC and it works great with this camera. You need a fast card to cope with the high image quality. When recording in 1080/60 HD the images are simply beautiful. The camera also has SteadyShot (doesn't work in all modes) which eliminates practically all camera shake. I discovered it's even possible to mount the camera upside down and by turning the 'flip' software to 'on'. The images are recorded as though the camera was in its correct orientation.
I cannot praise this camera enough. I wish I could compare it to its GoPro equivalent. I do believe the GoPro excells under water compared to this camera, but I'm not at all worried about that. I have no intention of filming underwater. However, considering you can buy this camera and a very decent memory card for nearly £50 less than the GoPro, there's no contest.