I have the opportunity to work with a couple of top quality progressive reloading presses and can make a few comments that some folks might find interesting. Presses are the Dillon 550B and the RCBS Pro-2000. Having used Rockchuckers and a Co-Ax for decades I was slightly intimidated by the more complex progressives - probably because I am not good at following written instructions, hate to waste time reading when a person could be cranking. First, the instruction manuals were not as good as they should have been. Some assembly was not in a logical order, some info was lacking, photos were fair to good. This was with both presses. The RCBS is big and heavy compared to the Dillon - the difference being cast iron vs aluminum. RCBS is double the weight, much bigger in mass. Dillon went together easier. RCBS has five stations, rounds move counter-clockwise while Dillon has four stations and rounds move clockwise. Both come with powder measures, the Dillon is amazingly accurate considering it is low-priced and simple, the RCBS is their standard measure c/w micrometer adjustments - accurate and reliable but expensive. Setting up either model is a "get out the manual" deal for me - I am an un-mechanical person and also have virtually no ability to remember such things. This goes for changing calibers, or heaven-forbid, changing from large primers to small primers. Fact is they intimidate the hell out of me, about like trying to figure out a VCR. RCBS bolts directly to the bench, the Dillon is best mounted on a steel bracket that elevates it above the bench a foot or so. RCBS uses a more sophisticated priming operation, requires plastic primer strips that require more learning but they work nicely. Dillon uses a heavy protected tube system that is reliable, poorly explained in their manual. Setting dies is about equal, RCBS has an optional die that checks the powder level which is worth having. Probably also available from Dillon. RCBS will not allow the use of competition dies. Dillon comes with proprietory dies that are great. Powder spillage is a reality, easier to clean spilled powder from the head of the Dillon. I have only spilled powder a few times, messy and looks like hell. Need a small vacuum to get the kernels out of the heads. Operation of the two presses is reliant on total concentration, much more susceptable to disaster than a single stage. If a die is not adjusted properly you make a lot of bad rounds in a hurry so you must make sure everything is bang-on before you start. Also you MUST get into a rythm and not get interupted if you want the machines to work well. Main thing is that you have to keep thinking about what you are doing, not just pulling the handle. I like to do batches with my single stage so I am more likely to do repetitious actions, not so with progressives as you must ensure that you put a case and bullet in place, check that the powder dispensed, primer depths etc. Leverage is good with both presses, particularly going up. Like any press the brass must be lightly lubed, outside and necks or you will have problems. The RCBS is a brute, biggest press that I have used. Ammo quality - cannot say that I can detect any difference in my rifles, 1/2 minute rifles continue shooting half minute with ammo from the progressives. I believe that there is a difference in super accurate systems, but I am making ammo that is reliable and accurate enough for most of my shooting needs. Unless you are shooting benchrest the ammo is probably OK for most long range shooting. I use it out to 1100 yards in the .308's and seem to do as well as with factory match or ammo from the Rockchucker. Bottom line - they spoil a person as you tend to get into a "speed" mode where you want to get a bunch of ammo built and get onto other things. Another bottom line, I thought I had it made with the two big progressives on the bench, after a while I realized that I had to have a single stage. Just too many small reloading jobs come up that don't require or justify the time to set up a progressive. So far I have had fewer problems and headaches with the Dillon than the RCBS. A friend who is a maestro with the Dillon line of presses came over and worked with the RCBS - he is staying with his Dillons. Factory backup has been superb - both companies have great people on their helplines. The two presses are inherently good machines, take your pick - Blue or Green.