^^
I honestly don't understand why the 550 exists.The price diff is not that much between it and the 650. Unless money is really and issue go with the 650 and a case feeder and you will never need to upgrade. I know many people who laid out money for the 550, tool heads etc... and later upgraded to the 650.
The only reason to go 1050 is if you are dealing with tons of crimped brass. But then again, if you have the money for the 1050, buying uncrimped brass is likely not an issue.