Every die set has its features and its detractions. I like Lee bottleneck rifle dies pretty well. I like their pistol powder thru expander die also, which design, as I understand it, Dillon is using, and paying royalties to Lee for the right.
The one thing I really like about RCBS and Lyman straight wall pistol dies is the expander plug which, when properly used, allows the seating of cast bullets without shaving or compressing the alloy, which to my mind at least, renders a more uniform cartridge. I do not care for the screw and lock nut type of seating depth setting on the RCBS dies, as it is much more difficult to fine tune seating depth with this arrangement than it is with Lee seating dies, which use the thumbscrew to accomplish this. The screw and locknut work fine on pistol ammunition, once you have arrived at a proper seating depth. It is a "set it and forget it" sort of thing.
Even better, in my opinion, are the Whidden dies for rifles, but you pay a whole lot more for them than you do either of the RCBS or Lee dies.