I started out with a Dillon 450. No Tool Head, and no Star Wheel. Other than that it worked very well.
I sold it to a friend and replaced it with a 550. It was a very good reloader. Probably four or five years ago I got a chance to pick up a couple of as new 550's. My old 550 was sold to another friend, and I upgraded to the newest version of the 550, and my brother picked up the other one.
I have added Dillon Dies over the years in 38 Special, 40 S&W, 45acp and a second set for 45GAP. I also have 44 Magnum, I believe my 480 Ruger dies are still RCBS.
I prefer to index the rounds myself. I have a light so that I can check the case for powder. I also like the slower pace which allows me to check each primer to make sure it is in place and facing the correct direction before seating.
I am perfectly happy with the 550, and have no plans to upgrade to a faster press.

Bob R