S&W does the finish & mounts the sights on that model.
I have the .40 M&P with VTAC sights, in my case I find 'em quite useful.
I need contrasts nowdays & the VRACs provide it better through a range of different lighting conditions than anything else I've seen.
Can't comment on the slide finish, since it hasn't been carried, but even if it does wear off, wouldn't upset me too greatly.
Denis