Well having a bit of experience with things CZ, the new SST 455's are out, and I'm pretty impressed but for the most part I prefer a system called the Poor Man's Trigger Job using Auto feeler gauge leafs for shims and springs available from a variety of sources. No one will make you "switch barrels" on your 455 and the attachment method is actually quite good, I have something on the order of 20 CZ's and 3 are 455's and I've not switched a barrel yet. Accuracy wise I'm finding the 455's to run right with the 452/453 but personal preferences are just that.....personal.