I had one done on a 627-2. It came home with ratchet/cylinder bind, far greater than it should have. It also came back with an oversize hand, instead of replacing the extractor and putting a standard hand in. It's been back for work twice since then and is going back again for a hitch in the trigger pull. I already have the shipping label. After this, I'm going to find somebody better than me if I need that kind of work done. The most obvious improvement was polishing the yoke barrel, so much so that the back was rounded where it was peened to eliminate the endshake.