IN MY EXPERIENCE:
Chrome resists rust better. But does sometimes chip, and is vulnerable to rust at those points. Chrome is generally easier to read the markings. Polished chrome can be slipperier when greasy. (Not matte chrome)
Black oxide resists rust generally fine for my purposes. It looks better when it's greasy, (It doesn't show the grease as bad, since grease is almost black). It can occasionally be a challenge to read the markings, depending on the circumstances. It's not as slippery as polished chrome.
As the user, you pick which benefits/problems you'd rather have.
I personally don't really care that much. I have some of each. All things being equal, I'd choose matte chrome, then black oxide. Polished chrome last.