Depends on the bass, the wood itself. There's a lot of factors that would make me either dislike, or love a natural guitar. I've only got 2, sorta...
The middle bass is a maya grabber copy, My only factory natural bass. The thunderbird next to it is my own, that i built from the ground up. It was nice in natural & even has a knot on the top side. The black is me using a blowtorch along the whole bass, it's an effect i wanted & it's still a natural feel. The last bass, although stained in black, was another build i had done, this time for a good friend of mine. It was left natural at first, but it looks better now in full black. its thin enough to be transparent/give a road worn feel.
I used to own a black goya precision bass i found at a pawnshop for cheap, & i had sanded the whole finish down, & left it natural too.
Sold this to a friend of mine, it was a nice bass in this config, but it sounded too much like my other maple board/black body pbass copy, so off this went. Still play it from time to time when i jam with her, she's writting some pretty weird stuff it's fun