I considered Dillon, Hornady, RCBS. I road-tested all of them. If you need power feed, go blue (dillon). If manual indexing is satisfactory (I wanted this for a variety of reasons), give serious consideration to RCBS Pro 2000 basic. For an extra $75.00 or so, RCBS now offers an auto-indexing Pro 2000. (You need to decide which you prefer...)
I went through extensive investigation, loading roughly 300 rounds on Dillon 650, Dillon 550, RCBS 2000, and Hornady LnL. I queried those who emphatically said "Dillon is the only way." None of the persons I talked to had ever used or even touched an RCBS 2000. It uses a strip priming system which is extremely positive and nearly fool-proof. Changing cartridge types is definitely faster and simpler on the RCBS. RCBS rotary powder measure (with micrometer) is more precise than Dillon sliding sytem and doesn't require regular fiddling.
Caliber Change-outs
If rim size doesn't change, I can switch from small primer feed to larger primer feed in about 30 seconds, by changing ONE part -- a threaded pusher plug. If I need to change the shell plate, a total caliber switch, with primer changes, takes a couple minutes. For a variety of reasons, unless you're cranking out HUGE volumes, I believe the strip primer system is better, more reliable and safer. RCBS also now has a nice, simple gravity feed pistol bullet feeder accessory.
[youtube]http://www.youtube.com/watch?v=wnfeTPZeOMQ[/youtube]
One note on the above video -- you can buy CCI Primers preloaded into the strips.
I suggest you try them all. Be sure you understand all that's involved with a Caliber/cartridge/primer size swap with the Dillon. If you decide to "go blue" that's fine. Dillon makes excellent machine. I would consider a 650 if I was loading 1000 rounds a week. But I recommend that folks do their homework and try red (Hornady), blue (Dillon), and Green (RCBS). Customer service from RCBS has been outstanding for me.