I bought a new Dillon 550C a few months ago. At that time, Dillon dies were on backorder and the expected shipping date was 7 months. The machine and one caliber conversion kit arrived in about three weeks. In an effort to get loading asap, I found a 4 die Lee set in 9mm. I got everything set up and am producing some very nice cartridges. Once the Dillon dies arrive, I may consider selling one set or the other. The Dillon is a three die set, the Lee is 4 dies including the factory crimp die. Does anyone know of any compelling reason to keep the Dillon instead of the Lee?