I picked up a 4506 a couple years ago and it is great, fits nicely between my 645 and 4513tsw. I did have to give it a trip to S&W to replace the extractor; S&W will not sell one they have to install. Not bad though only cost me $14 for postage for my local gunsmith to mail it in. So far it has been perfect since comming home, that solved the only problem (extracton) I have found with any of the three. Jim.