"I don't have a problem with the standard dies but I figure if all the bench rest guys are using them there must be a purpose."
Winning BR guys don't use threaded dies and presses, that label is just hype. But, the Forster's and Redding's copies are unique in that they have a spring-loaded full fitting chamber that fully contains the case and bullet in line before seating starts. That virtually duplicates the 'straight line' (Wilson type) searters BR shooters do use so the label does have a bit of justification.
RCBS's (and Hornady) costly seaters only have a very short, gravitey fed (sloppy fitted) alignment sleeve that ONLY holds the bullet and neck, not the full case, so they aren't as dependable as the other two.
Fact is, common seaters are usually pretty good and, if the tolerances all work right, any of them can load about as well as a much more costly seater. So the question of getting a new seater help you make better ammo depends a lot on how well your current seater is doing. No seater can make straight ammo with bent case necks and that's the biggest cause of runout. Second greatest producer of runout is probably excessive "bullet tension" (undersized fit actually) that pushes the bullet out of alignment during seating; all we need is a neck about ONE thousanth smaller than the bullet, not the three or four thou a lot of loaders seem to seek!
The costly micrometer seating heads are user convienences only, they can't add anything to the ammo. If you want them, pay for and enjoy them. I have a couple but quit buying them (Forsters) because I'm going to set my seating depth with my dial caliper and bullet comparitor anyway.
