A 1050 would be wonderful but my fingers aren't nimble enough to place the bullets quick enough to make a 1050 a worthwhile upgrade for me...now a 1050 with a Mr. Bullet Feeder would be a dream machine for reloading. You can use a Mr. Bullet Feeder on a 650 but you either give up the powder check or go with a combined bullet seater and crimp die.
I think the two or three big practical advantages of the 1050...over just about any other press...are
a) primes on the down stroke gives an adjustable depth and more reliable seating of the primer
b) more stations, have room for case feeder, bullet feeder, case trimmer, powder check, resizing die, powder drop, expander, bullet seater and crimp all in the cycle, 650 only has 5 stations
c) having a separate powder drop and expander station provides better control of powder on full capacity loads. This hasn't been an issue for me.
Disadvantage of course is price which you already know, but also be aware the calibre conversions and quick change kits are also 2 to 3 times as expensive for the 1050 over the 650.
The case feeder on the 650 works great and is the same unit as the 1050 (except for the mounting). I've never had any issues with mine.
I load .45 Colt, .45 ACP and .38 Special. I don't have experience with .223 on the 650 so can't testify there.
Advantages of 650
a) Switching between calibers on the 650 is fairly easy and only takes me about 20 minutes
b) Lifetime warranty over the 1050 1 year warranty
For what its worth, if I had the money and was doing it again, I'd get a 1050, but I have no desire to upgrade what I have. I've loaded 10's of thousands of rounds on the 650.
Biggest heads up I can give anyone is to be very, very diligent about ALL the adjustments noted in the manual. Some of them can seem a little pointless but trust me, all of them are necessary. The 650 should run absolutely perfectly, if it isn't then something is out of adjustment.
One important upgrade on the 650 which I've done and I think is very popular is to get the small thrust bearing for the shell plate bolt. Does wonders and its cheap.
I bought from MD Gardner, great service and a very knowledgeable guy who is very well respected in the shooting community. I don't know if his prices or availability are any better than anyone else but his advice and service are great.