They work great. I use them on my .223, .22-250, 6 BR, 6.5 CM [the new expensive one] & .308 W.C.F. seating dies. Are they worth the money? Certainly the older ones were/are. The [1 member] jury [me] is still out on the new, more expensive, version.
I'm not sure if they will work on RCBS dies, but they will work on older Pacific dies, as that is essentially what Hornady dies are, since they bought Pacific in '71, before Hornady made any loading tools & were simply a bullet maker.