I have the DIP also on my CZ 455. Took it off a few weeks ago for a thorough cleaning. I really didnt notice much marring, but you could tell where the screws had been. But like the above posters said, in normal circumstances, it never comes off the gun, so it's a non issue for me.
I had not seen the Murphy rail, that is pretty slick. If money was not an issue, I would like to give that one a run.