I just ordered one. The Summit appears to be a copy of the Hollywood Senior from the Hollywood Gun Shop.
I'm guessing that RCBS had to do something to skirt the patents, so they flipped it "upside down" so the fixed part would be at the bottom and the sliding part would come down from above, and they reversed the relative positions of the shell holder and die bushing so the shell holder would stay on the bottom part.
What I like about this design is it does not put a lot of torque on the front edge of the bench. It's very annoying when the press torques the whole bench top and rattles everything on it. I've seen the stoutest benches shake. What's more, I've never seen one that does not. It would probably take a cast concrete bench. I considering that, but bought a Summit instead.
To upgrade the Summit, you can get a cross pin that goes through the linkage instead of the two bolts. It somewhat limits the height of the die you can use but there's still about 4 and 1/8 inches -- taller than any die I have. This pin should make the linkage even more stout that the Hollywood.
Also, you can get the short handle from RCBS, but I prefer roller handles. This one from Inline Fabrication is short:
Another upgrade I see consists of a primer catcher with a tube adapter. I sort of doubt that I will decap much on the Summit. I will use my cheap Lee ABLP progressive with the case feeder. The Lee APP would also be good for decapping.
I most want the Summit for resizing rifle cases, and for bullet seating for rifle and handgun. I read some comments that it does not provide a lot of leverage compared to a Rock Chucker, but that it's similar to a Forster. I don't need to do any extraordinary resizing. I considered seating on an arbor press, but there is no die to do so for my handgun cartridge. I might get the Wilson seaters for my rifle cartridges to use with the arbor press conversion but I might also just get Redding seaters.
I don't have mine yet, but I am anticipating that one of the things about the Summit that will be different is the relative positions of the shellholder and the handle swing. Most presses have a handle swing that goes well below the press base and many people prefer to mount them on risers so they don't have to bend their back on the down stroke. I'm expecting the Summit will work better in a lower position because the handle is already higher. That means shell handling will be down around waist level rather than at my sternum.