I'm a little late, but I am a 550 fan boy and had this conversation with Brian. Pretty much a case feeder on a 550 is not a great thing. If you can afford a 650, it seems that is what the 650 is made for. 550 on a good day you can kick out 500 rounds an hour. If you want more than that and can afford it, it seems a 650 is the way to go...