How do I choose between a chrome-coated (nice and shiny) and an oxidation-treated (dark oxidized surface) tool, all else being equal - same steel, same design, same handles, just one has its metal parts chrome-coated and the other has its metal parts oxidized.
How do I make a choice?
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.
I prefer the oxide coating. The chrome tends to chip on the highest stress points. At least in my opinion the chrome is more slippery when wet than the oxide coating. Plus impact sockets are black, so black sockets and wrenches look tougher right.
I prefer chrome, because I expect it to give better rust protection. I think chipped chrome is a sign of defective plating and/or poor heat treatment of the underlying steel (not properly hardened). I would expect the chrome plated tool to be more expensive. If both price and features were the same, I would suspect they'd taken shortcuts with the chrome plated tool, and would buy the black oxide treated tool instead.
Chrome wears more, is softer than the underlying metal, at least if it's a quality tool. This creates poor fitment and loss of force, damaging fasteners, and it's more slippery.
There are only two good reasons to choose chromed. Either you're a monkey fascinated by shiny things (aren't we all?) or you're in an environment where it is difficult for you to put forth sufficient attention to keep tools from rusting.
