I quite fancy a Hero 5 Black with a chest strap, but am time poor and always felt as though Video processing and uploading was a chore I'm not prepared to justify.
Have things changed over the last few years - what time would I need now to go from recording on the Hero 5 to posting somewhere?
Most important point is to change the default settings in the GoPro, there are some good videos on YouTube detailing what to change and why, you should be able to get video that is good enough not to need post processing.
The only other thing to bear in mind is the latest Hero 7 in black has extremely effective image stabilisation that is as good as using a gimbal, for some reason only the black one has it!
Here is a review of Hero 7 for mountain biking: