I started out with an RCBS single stage kit and I later bought the digital scale and dispenser. It's a bit slow, but accurate. It did a good job when I loaded a hundred here and there, maybe a long run with a thousand. The hand trimmer was shit and I hooked up a DeWalt (without the kit, I just chucked it on there).
Now I have a Dillon 650 and DAMN that's nice! I use two heads per round plus another block with nothing but a decapper on it. One block has the auto trim die setup and size die, the other has the powder dispenser, load check alarm, seating die and separate crimping die. I no longer use the POS trimmer, the Dillon trimmer is uniformly SPOT ON per the Wilson gauges. With good dies, the Dillon press can load ammo as good or better than the single stage. When setup right, it's solid and the die operated powder dispensers are amazingly accurate (generally +/- .1grain). I was really surprised here, I haven't had good luck with powder dispensers being accurate, save for the Hornady .50 dispenser I have. For working up loads and for accuracy loads, I still use the powder dispenser and digital scale, it's faster than adjusting the Dillon powder dispenser for a handful of rounds. You can setup a funnel where the powder dispenser goes if you like for this, and I've seen setups where a guy was running 2 or 3 of the dispenser/scale combos in order to speed things up. I have one and just pull it off the press at the seating die and charge it and put it back. Once I have load data, I set it up and crank it out, testing random loads for uniformity, which is amazingly tight. 650 is also fairly easy to work on and they make all the parts available for it.
I also use the Dillon .50 press. That's a solid piece and excellent (really the only option) for loading for an M2HB. But it's also just as good for bolt guns. It's more die dependent too, like I say. I use CH4D for the .50, but there are others. It does most everything, including auto trimming. But it doesn't do everything, I can't decrimp despite it having a priming die that could double as one if they made the part.
Reason I bring that one up is that with the 650 and .50 press, I still use the single stage RCBS, but not for loading much, I use it mostly now for decrimping .50 brass (the bushing can be removed for larger dies) pulling bullets with a collet puller, and if I need to run a bunch of rounds through one die, say a crimping die or something, I may do it using that since loaded ammo won't feed into the 650. It gets used enough to be installed right between the two Dillons.
I don't like the priming setup for the 650 that much either, but it works. I'd have liked the 1050, it's a different animal, but if you load any quantities of more than just 5.56 or 7.62 military brass (it has a built in decrimper) it's just not worth it IMO, too expensive for caliber changes. 650 isn't too bad, even if you get 2 heads, the stand, alarm, powder dump and accessories, even if extras (since 5.56 and .300BLK use a lot of the same small parts, it's nice to have spares for those). I'll get setups for all but .50Beowulf --I simply don't load enough of that to warrant a setup, I'll do that one single stage. So having at least one, even if basic, is nice to have.
If you load small amounts of ammo, a good single stage is all you need --unless you expand. If you have the 650, I wouldn't waste the money on it, especially if you already have a single stage. If you don't and want to drop the coin on a Forster, it's nice, but I think a used RCBS at a gunshow or online for cheap would be as good, especially if you take full advantage of the 650. I feel one or two of those digital scale/dispenser combos is, however, well worth it. Although you could just as easily get away with the powder dump included in the RCBS kit and a trickler, that works well too. If starting out, the Forster or RCBS Ammomaster would be best for single stage, then you'll have a great single stage when you upgrade to 650. But it's not necessary.
Speaking of, if you get a single stage press first, why not get the RCBS Ammomaster? Even a used one would be awesome at the right price. It accommodates regular size brass with bushings and with that ram it's gotta be easy to use. If I needed a single stage, I'd get that, but I'm .50 biased too. Still, I think it's a solid press and would be great for an adjunct single stage. Large rams and long handles really make working brass easier.
What I have and how I do it is based on years and on the quantities I load. I typically run 2000+ per, way more if I have the brass and bullets. I have 8000 pieces of .50 I have to work... So Dillon has become my friend and I was skeptical of how accurate ammo loaded on those machines could be until I started using one. Keep 'em tuned, do random checks, and it'll work great.
Good luck, the 650 is the best press unless you decrimp a lot of LC brass. The Dillon decripming tool is really nice, but not when you have thousands of pieces to do! A 1050 would almost be worth it in addition to the 650 if you have enough 1 fired LC brass to work.