Need advice from experienced GoPro users

[DeJay]

I have a Hero 4 Silver, my wife bought it for herself and it drove me nuts trying to match the footage to my camcorder in post. Main dislikes are barrel distortion, a colour balance that seems to keep changing and soft image quality after distortion correction. Then again, it's a handy little camera for many uses and deserves a little perseverance and understanding on my part.

I have seen many, often conflicting, tutorials and done some tests, this is why I ask for your advice. It would seem that if I shoot in 2.7k Wide, after correction losses I should finish up with good, sharp 1080 video. Also if I set White Balance to Native it should stay constant and be easier to correct and match in post. If not, what would you suggest? I have ProTune on, set to Flat with Exposure Compensation at -1 to try to achieve the highest dynamic range. Again, would you agree? Any other settings I ought to tweak?

Also I am considering getting a set of ND filters for it and was wondering if it's worth the effort. Any brand you would recommend (or avoid)?

Any advice will be appreciated.