I have a 625-6 Model of 1989 with 5" barrel and have a 625-8 with 4" barrel. These are two of the most satisfying revolvers I own. I have put in excess of ten thousand rounds through mine and look to put another 100,000 or so rounds though them before I hang up my spurs. The cylinder throats on both of mine are perfectly sized (.4525") and they both shoot extremely well.
625-8 Jerry Miculek Special (not a performance center gun):
625-6 Model of 1989:
These are extremely easy to load for (I shoot ONLY my own cast bullets in them). They work perfectly well with moonclipped .45 ACP's or .45 Auto Rim cases.
I can't help you regarding whether to buy a "standard" or a Performance Center gun. I have a Model 629 Performance Center revolver and would probably have been about as well served with a standard issue 629. It is pretty and has a slick action (as you would expect) but it cost considerably more than a standard revolver. Like I said, it's a Personal decision.
Dale53