Just a comment on the Hornady progressive loader: After several comments here and other places, I looked carefully at them on a few websites. Hornady's website wasn't that useful for providing detailed info about any of their products and that's a shame since Hornady makes good equipment in my experience. MidwayUSA was useful, especially the reviews and links to related products. From what I found out, the dillon 550B and Hornady progressive are actually quite similar in cost and capability.
The big difference is the hornady can use a casefeeder (another $150-200) now. Dillon showed a prototype casefeeder for the 550 at the SHOT shot recently, but it'll be in the $220-240 range and available in Fall2005; neither is cheap.
The hornady is a 5 station press and the dillon 550 is a 4 station, but the dillon expands the case mouth and drops powder in a single station. The hornady uses seperate stations to expand the case mouth and drop powder. The 5th station advantage isn't an advantage because there's no easy way to add a powder check die while having seperate seating and crimping stations. The Dillon 650 is a 5-station press and uses the same powder system as the 550 so it DOES have an open station for a powder check die. It seems there are limits on what dies can be used in the 5th station of the hornady and the Lee FCD (a popular finishing die) won't work easily there.
Conversion costs seem to favor the Hornady, but not by that much. Shellplates from both cost about $25. The powder funnel that dillon uses (to make a 4 station press work) isn't required for the hornady since the expander die from the die set is used. Both presses use powder dies that require adjustment and should probably have 1 per caliber; about $10 each. Dillon has toolheads that holds a calibers-worth of 4 dies for $13 where hornady has "locking bushings" that are about $3.30 each in bags of 10. 4 bushings would be required for each pistol caliber; call it a draw at $13. Dillon uses locator buttons ($1 each) that hornady doesn't seem to use, so maybe $3 savings there. One thing to realize is you don't have to buy a complete conversion kit for every new caliber on a dillon 550 IF you have a powder funnel, shellplate, or locater buttons that are required for the new caliber; the parts can all be bought individually although it is nice having everything for a caliber in little plastic case. Conversion/setup charts show what is common and what is different for loading different calibers.
The other serious difference is manual vs. auto-indexing which doesn't make a noticable difference unless you have a case feeder. Dillon hasn't said anything about auto-indexing a 550 to go along with the new case feeder, but it wouldn't be hard (I thought of a way) and I wouldn't be surprised if it became an option with a case feeder. No inside info here; just speculation on what could be done.
After the comparision, I decided to keep my Dillon 550 setup because changing over to the hornady would have saved very little, if any, money for me. I also think the dillon powder measure is a better design for progressive loading. I have the hornady measure and it's a great bench-top measure. Mine is old enough that it came with the micrometer adjustments standard (now they are costly accessory).
Either will work, figure what you really need now and where you'd like to be reloading-wise in 5-10 years then make your choice. If you choose wrong, there is always ebay