Consider your overall output, number of calibers you reload for, and the type of those calibers (rifle, pistol, or both)
When you decide what your output requirements are, that can help to determine the attributes of the press.
As an example, while the 550 isn't much slower with the manual indexing than a 650, that changes with the incorporation of case and bullet feeders.
(and the 550 case feeder is a half-hearted attempt that only works on pistol calibers).
The 650 is the best bet, imho.
The Hornady LnL is another decent choice that lends itself a bit better to customization than the 650 - especially if you have several different types of loads taylored in the same caliber, and don't want to fiddle with die set ups.
When the dust settles on the different set-ups, the LnL and 650 are going to cost about the same.