Here are my exceptions to the above rule... I like micrometer seater dies particularly where I might change bullets and cartridge overall length frequently. I record the setting of the seating stem and it makes returning to that setting easier. But for cartridges like for my M1 Garands that I do not change bullets, a standard seater die works fine, it never gets adjusted. Hornady has an economical solution with a micrometer head that replaces the stander seating stem adjuster. An economical upgrade. RCBS Gold Medal seater dies are great for loading rifle cartridges on a progressive. You put the bullet in a window in the side of the die and it gets seated. I load 204 Ruger on my RCBS Pro2000 with one of these seater dies. They are a bit pricey for some cash limited folks. For semi-auto rifles like the AR-15, I get small base dies if they are available for the cartridge that I am shooting. I have AR-15's in at least 8 different cartridges. Small base dies are cheap insurance against chambering problems which I have had. I do not see any loss in case life with small base dies. If you buy them from the get go, they are not any more expensive than standard dies. I have some bushing dies for a cartridge or two. It is a nice idea but cases need to have uniform case mouth thickness from case to case. I do have a 22 x 6.8 wildcat rifle that I use a bushing die to reform the 6.8 SPC case down to 22 x 6.8.