I should add that I've loaded under 1" groups off of the dillon 650. And I know a guy here that shoots high power with ammo he reloads off of a 650.
One thing I won't do on the dillon is push loads to max, I use the single stage. Then hopefully once the max is established, find an accuracy node with a bit less powder.
I really shoot try loading some .45 on the dillon and compare it to the single stage and see what the difference is. Also, you can mount a normal powder measure on the reloading die, dillon has an adapter for that:
http://www.dillonprecision.com/#/content/p/9/pid/23634/catid/3/Powder_Measure_Adapter. It'll slow you down some, but if it throws a more accurate charge, why not not spend the time.
Of course, if you have a machine shop, you can build your own - and then make it really tall so you get a nice long drop to get the powder compressed.
Oh, and I get 3-400rds/hour with a 650, when loading .45ACP. Don't want to know how slow it is to do rifles (once I figure all the time spent with case prep, multiple passes through the press, etc). I actually like the priming system, at least compared to dad's old RCBS progressive - that one sucked ass. I really need a case feeder and the primer filler. Once there, I should be golden.