Looking to get a spare battery for my Hero5. Any reason to spend the extra and get a genuine one or will a copy work OK?

If you get a genuine one you know what you are getting, by nature of a copy it’s whatever they put on the label.

Go genuine. I bought some highly regarded alternatives and they last nowhere as long as the genuine one and are getting progressively worse aven though they are not very old.

I’m sure I read somewhere that the aftermarket ones don’t work in the Hero 5 after a recent software update. I may be wrong though.
For the sake of a few quid I just went for a genuine one.

Genuine it is then, any better deals than £17.95 on Amazon?