Top positive review
Buy the one without the e-commerce packaging.
March 26, 2018
Understand that by purchasing this option, you are risking receiving a broken/damaged unit that you might not be able to return in some instances.
I really don't know the extent to which buyers are getting bad units, but judging from the reviews it is happening substantially more often with the E-commerce packaging option. It appears that this "E-commerce packaging" is, at least in part, a way for gopro to resell it's refurbed/returned units. Personally I went with it because I was in a time crunch and the shipping option was faster at the time. For the record I received a working non-blemished unit, however my advice is spend the extra $8 or so and wait the extra shipping time(if applicable) and get a unit (B01M14ATO0) that you can be more reasonably assured is in good working order.
Also from the reviews, I don't recommend submerging the unit in water despite the company's claim that it is waterproof. If you are going to put it under water you should get a protective case, and the fact that there are numerous options on the market (including here on amazon) is a clear red flag. I haven't put the thing in water, nor will I. From the looks of the unit I can say that if I didn't know any better, it never would have occurred to me that it could safely be submerged in water. Additionally, I read in the reviews that the company does not cover water damage under the standard warranty that comes with the unit; it's worth looking into. If you plan on going underwater with your unit you should know whether the warranty covers water damage before you buy.
I got this as a tool to help my son improve his motocross skills. Being able to watch and discuss the footage has helped, but I have yet to see whether it will be $300 worth of help. Time will tell. Immediately after filming, you can wirelessly stream full clips from the unit to your smartphone with the app relatively seamlessly, but that would probably depend on the phone (S8+ in my case). If you have a tablet or laptop to bring to the track, even better.
Suggested extras that you're going to want:
At least one extra battery and the external charger for when you are out and about: B01LZHRYJS
Front and back adhesive screen protectors: B01M8J9ONB They are cheap and easy to replace. The unit's glass lens cover and rear screen not so much. Well worth the $10. I haven't noticed any issues in touch functionality as a result of the protector, nor have I noticed any problems with video quality.
Another thing to think about is extra mounts and adhesive strips for when they go bad or you want to place multiple mounts at once: B01L13RXBS
Finally, a decent carrying case is worth it. This camera is an expensive piece of equipment that you don't want to be just throwing in your back pack or whatever it may be: SM1408005
The specific products I suggested are what I purchased, and have worked well so far for my particular needs. Obviously go with what suits your needs best.