I like them on my MM Stingray, as they take that metallic edge off of them; they are-to me--the perfect complement to brighter-sounding basses.
+1 Exactly my experience as well. Sound great on basses that have a tendency to have a zingy top end (like stingrays and G&Ls). Really tames the top end and reinforces the bottom end. I use them on all my rays.
I can't stand overly bright sounding strings and the DR Black Beauties are about as good as it gets in not being overly bright but still having very good definition on the top end and not muddy on the bottom end. I'd call them warmer and darker than a stainless or nickel round wound, not as dark and more defined than a tapewound, much more defined than a flat wound and 5 to 10 times longer lasting than a typical round wound (I have one set that's on year 4 now).
I only play finger style so I've never had any problems with the coating coming off due to my picking hand. I understand they did change their coating material very recently so it's even less likely to wear off with the newer sets. The only issue I've had with these strings is when feeding them through the bridge on an initial stringing. You'll want to feed them carefully so they don't scrape too much on the bridge as you pull them thru the holes and over the saddles (assuming you don't have a top load bridge) otherwise you will scrape some of the coating off.