I don't think there's any difference between either make's full length sizing dies. But their full length bushing dies are much better than the standard ones; Redding's type S full bushing or RCBS Gold Medal full bushing dies. They have interchangeable bushings so one that's the right size for your cases will size the fired case necks down just right without having to use an expander ball like the standard dies use. Case necks are much straighter on the case shoudlers and the cases can be resized more times.
Once fired cases are full length sized in a bushing die, most any seating die will put bullets in them very straight. If the sized case neck's not the right size and not straight, no seating die will straighten it up enough to matter. Therefore, I don't think you need to replace the seating dies. Bullet runout on a loaded round can be up to 1% of the bullet's diameter and excellent accuracy will prevail.
US Navy Distinguished Marksman Badge 153
Former USA Palma Team Member
NRA High Power Long Range High Master
NRA Smallbore Prone Master
Last edited by Bart B.; January 10, 2013 at 01:22 PM.