I'm not a Lee lover or hater. I use what works best for me.
The Lee collet die offers some unique features vs. other dies:
- It is less hassle to use since no lube is required
- Typically it produces resized brass with less neck runout than using other non-bushing dies for sizing. Expanders can pull the neck off center when they are pulled back through.
- Brass life can be longer since the neck is worked less than running it through a typical sizing die then expanding it
If you use a bushing die with the correct bushing for your brass neck thickness, you get most of the same benefits but at a higher cost.
The Lee collet die does take some learning since it works differently than other dies. It helps to take it apart before you use it and check for chips or other reside left by the manufacturing process. I polish the mating surfaces between the collet fingers and the taper they contact against. Lube this surface to prevent galling. And do not operate the die without a cartridge in place. It can cause the collet fingers to reduce the opening and can buckle the shoulder of your brass when you try to size it.