Healthways didn't prep their metal very well, and got a very rough surface on the Scuba and the Deluxe. The chrome seems to be relatively durable, though. The GL seems better (prettier).
My Sportsways regs are really nice.
The early DivAirs had a nicely chromed cover, but every late one (plastic body) I've seen sucked. The coating was very thin and always worn away.
You're right about some of the USD stuff. Every shiny chrome DA and RAM I've had or have is covered in tiny bare spots.
The nicest chrome I've seen is on the Spiro Mistrals. That is a nice chrome job! Their rubber lasts as well.