I use Dillons & have a couple 450s, a Square Deal, a 550, & a 1050. All are good machines. A friend has the Hornady & another the RCBS. I have nothing against any of them, just started with the Dillon & will stay with the Dillon.
A note: If the bullet is seated in station 3 on the 550, you will have to advance the shell plate before you can rid yourself of the bullet in your left hand. This prevents a double charge at station 2, or at least it does for me. Just a thought.