If you follow Lee's directions and turn the die in finger tight, not turning by the lock ring they are repeatable. I like them because they allow the die to float a bit as I feel it helps center the cartridge. I think RCBS rings with those cheesy brass socket screws are the worst. Even with the lead shot under the screw they slip and strip out. I replace them with brass screws of the same thread pitch. They seem to hold then. Hornady's are good too. I have all three depending on the dies they came with.
Invest in precious metal...buy lead \m/