I own an RCBS Supreme and a Dillon 650 and find I use both, often to do various stages of work. What I mean by that, is I often use the 650 to decap and size both rifle and pistol cases, which then get thrown into an ultrasonic cleaner. It just saves time. Once they're dry, especially for rifle cases, I'll prime a few hundred on the 650 and store them. When It comes time to make some rifle loads, I'll use the pre-primed cases and my Hdy powder dispenser to load, and the RCBS to seat and crimp (If I'm crimping). It's funny, it seems like it's much less work to simply pull 50 cases out of the cabinet pre-primed and fill and seat them.
If I'm doing plinking rifle, I make them on the 650 - way faster of course. If I'm making volume pistol, 650 all the way. Still do the decap and size first then US clean, so it's kind of a 2 stage process.
When I'm doing 50-100 piston rounds (say 44 mag or 357) I'll prime, load and seat/crimp on the rcbs using the powder dispenser. Doesn't really take that long and the process is a nice calming influence.
Since you already have a nice SS press, you obviously buy quality. I'd suggest you look at the Dillon 650 with a case feeder and consider it a buy once for lifetime purchase. It gives you lots of options when you have both.