I used to have a Harrells combo press which is different than the press they sell now but has the same clamp. I think they're best with custom dies or just light sizing in general because the clamp isn't all that robust. I haven't used the Sinclair but I see them alot at BR matches but you're limited to 308 length cases. The Summit is the most versatile obviously.
At the range I've used arbor presses, Harrells combo, Rockchucker, and currently been using an RCBS Partner for a number of years now and it's by far my favorite of those four. It's a light duty press but robust enough for doing what I need at the range while light enough to easily move around. The Rockchucker works fine but it's noticeably heavier to carry around. I don't know the weight of the Summit but I'm guessing it's similar to a Rockchucker give or take so I'm thinking it's probably not the most convenient thing to haul arouond. For me though, I have a lot of hand dies and there's an arbor press conversion for the Summit so it could be a one press for everything even if it's less than ideal wieghtwise.