The new HERO 5 continues to suffer from a few of the earlier flaws, such as washout when shooting in the general direction of the sun or an area of water reflecting sunlight. So far I haven't noticed the HERO 5 draining power as quickly as the first gen, but I took the company's advice to use lithium batteries in the cold NorCal water. There is still a lag time, both in starting up and in activating the shutter, which has led me to take accidental videos (by pressing the "on/mode" button twice because it didn't appear to be on but was, thus switching to video mode), and to miss shots or capture my face against the sky, looking at the camera. Although the features, quality and capability have expanded, the external design remains the same. The tiny black icons on the low-contrast screen are hard to make out and the controls and strap can be a bit difficult to use while wearing 2-3mm gloves.
The HERO 5's built-in memory needs to be supplemented for video use or heavy photography, and the upper limit is a low 2 GB, although GoPro's website promises more in the future. Movement of the camera can cause interesting distortion of the subject matter, like this:
Another drawback is that all photos transfer over to a computer with a hardcoded date of January 1, 1970 - what is that, the birthday of GoPro's founder?
All of these are relatively minor concerns, and hopefully GoPro will remedy them in the next release. For its main purpose, taking on-the-water photos and video, the HERO 5 does a pretty good job. Right now I've got the default setting on 3-shot photo burst, but since I've recently added an SD memory card, I'll be taking more video soon. Here's an early attempt, and my first upload to Vimeo: