I have several (6 to be exact) of them on my dies and love them. You can adjust the die without removing it from the press, which (imo) makes it easier to fine tune the depth. Once set, the die returns to the same place. Meaning it can't be rotated. It will only go in one way.
I get more consistent shoulder bump measurements since switching to them. YMMV
I agree with Quiet Texan, all the products I have purchased from SAC have been top quality.