I use my 650XL for most of the revolver/autoloader calibers I shoot in bulk: .38 special/.357 mag, 9mm, 380 acp, .40 S&W, 45 ACP, 45 Colt, 41 mag, 30-'06, 308.
I still do rounds for accurate bolt action rifles (300 H&H, 308, 30-'06, 6.5 CM, etc.) on a single stage press.
I only use my 1050 for .223/5.56. I shoot a fair amount of .223/5.56 (10-20k/year) and removing the primer crimps on the Dillon hand swager was getting old. I had a very hard time keeping the brass that I had already run through the swager separate from once-fired stuff I'd found on the ground or bought, so I ended up hand swaging all the cases for each new ammo run. I spent a lot of time thinking about getting a 1050 and got it mostly because it removes primer crimps automatically.
Also, I was loading a lot of .223/5.56 with friends at the time. I agreed that I would load their stuff, if they did the case prep (including doing the swaging!). They didn't like using the hand swager in volume either, so they agreed to absorb part of the cost of the 1050, so that made the decision a little easier.
If I had enough ammo demand to keep a herd of 1050s set up continually in only one caliber each (like jmorris) the 1050 is a great machine. Having one 1050 and changing calibers regularly, isn't so great.
If it was just me, and I had it to do all over again, I'd just stick with my 650XL, and tough it through the hand swaging. Or maybe get one of these adapters that purport to swage .223/5.56 cases on a 650XL:
http://www.uniquetek.com/product/T1568-6