Here is my opinion on the Summit after owning one for a few months. As a back ground on myself, and my experience. I have been loading ammo now for over a decade, load for several different calibers, and usually average about 500 rounds a month shot/loaded when I'm on a roll and that has been pretty consistent. I have been using the Summit for every process since I have bought it and comparing it to my Rockchucker. I have yet to find any of the issues stated here except for some screws coming loose when it was new. Sizing with the long handle is fairly effortless and about on par with the rock chucker. One must remember that the die plate on the Summit is HEAVY especially with a die, so the down stroke of the actual sizing of a case for me personally is easier. It requires less strength and less "body weight" so to speak compared to a traditional style press where it is up to you and your arm strength to push the case up into the die. Pulling the die off the case (case out of the die?) can take a little more effort. A good case mouth lube or regular old case lube here helps here because of the weight of the die plate.
Bullet seating speaks for it self. I have rather large hands and have had issues for years with my Rock Chucker where I will occasionally have issues fitting my hands into the frame and dropping a case full of powder. I don't have this issue with the summit, and seating a bullet is effortless. Many have also noticed that due to all of the slop in the linkage, that run out is a lot better; I have noticed this as well. I would even go so far as to say that ammunition loaded on my Summit is a smidge more accurate than ammo loaded on my RCIV.
As far as on press priming goes, I don't really care. I have used my Lee ram prime with it but I still stick with an autoprime. I wouldn't let this stop me.
With all of that being said, would I recommend this press as your first press? No. Die set up is a little different from a traditional press, and thus a little bit of experience is required here to make sure you are setting up your sizing dies properly. The instructions included with the press on die set up aren't exactly correct. The reason for this is the slop in the linkage, which is by design. You have to get all of the slop out of the linkage before you can actually set a shoulder back. Tools to measure this, cause gauges, or simply screwing the die in until it touches the shell holder, and then continuing to screw the die in until you see the die plate raise up and the slop taken out is sufficient. Not only that, it just makes more sense to learn on the type of press most manuals are using when they were written. It takes the confusion out of things because this press is essentially "upside down".
Hope this helps. It's a good press either way and it has it's place on my bench... I love it.