Article in Handloader a couple issues back reviewed the x-dies. They were a bit of a hassle if you had more than 1 lot of brass to size, but they worked for their intended purpose, in that after the initial trimming, no further trimming was needed for 10 loads. If you really hate trimming, go for it, but otherwise, not really worth the hassle or expense. The guy had a friend who was loading for a 30-06 Machine gun, for him those dies were an invaluable time saver, otherwise.......