The Whidden floating die toolhead are awesome. I have them on almost all my 550 caliber conversions.

I am partial to the UniqueTec micrometer powder bars. For small charges the Arredondo bar with the UT micrometer is an excellent addition. Most all the powder bars I use often have them. For a set it and forget it, the stock Dillon is fine.

I need to do a new write up on how to tweak Dillon measures so they throw stick powder better. I have a new measure I need to polish up here in a week or so. I will take some pics.