Cap, I have the RL 550b. Nothing negative about it or Dillon. This was my first purchased press. Will handle any pistol cal. you can throw at it except .480 & .500S&W. Dillon will not make dies for them. They[dillon] said something about it would make the die walls too thin for them to "no bs" warranty them. Set up changes are a snap (about 5 min.) if you have dies already mounted in a spare tool head. Tool heads are about $20 and are highly recomended. If you realy want to save set up time buy the deluxe quick change assembly (about $90) it comes w/ a tool head,powder measure, powder die and a stand to hold all of it. The point of this system is to have a powder measure mounted and set and dies already in the tool head. just pull 2 pins, slide in a new tool head, add powder and start pulling the handle.
My next press will be the 650. It has a 5th station for a powder check and has auto indexing. These are about the only differances between the 2.
I have had no problems with cast bullets in my press, but I usaully use Berrys plated bullets.
If you load standing up you will need the optional "strong mount" as this raises the press up to a good standing heigth. The roller handle is something that I highly recomend. The ball handle it comes with will wear on your hand after a good night of loading(1500 rds) I also recomend the powder sensor. It will warn you when you get down to about 300 Gr. of powder. This will benefit you as I know you load some large cases and large cases eat powder at a fast rate.
If you have any other questions about the blue press I'll be glad to help if I can. If you would like to test run a 550b give me a call next time you come to the coast and you can swing by and I'l turn you loose on mine. I have .45ACP, .45 colt, .44 mag, .41 mag, .40 S&W, but only have the 1 powder measure so we will have to reset the throw weight on the powder measure.