I use'm too, sweet, simple, inexpensive and the same every time. Each stem is the exact length you need!
Use the Zip Trim too, It has clamping slots as well as screw attachments. I keep it off to the side and when I need to trim just pull it out, clamp it with a long reach clamp I modified a bit to fit the clamp spot. The base needed to be sanded flat with some 80 grit as the two plastic halves didn't fit well on the bottom (molding issues).
I bought a cutting head for each of my 3 cal's, and just got some wood ball from the Art's an Crafts store instead of paying Lee to glue one on.
Keeping the shell holder and case straight when useing the drill attachment was problematic, it would wobble the case neck (undesirable), getting the case in the shell holder and tightening was tough with one hand. The Zip Trim solved that, I can use both hands to position everything proper. Nice straight spin,,