I can't answer the op's question but i do have some thoughts to share. I used a splitter the other day, it's large, 18hp honda twin, log lift, adjustable 4 way that comes off and on easily. The very first thing I said to him when I backed up to hitch onto it was "why did they build it with the wedge at the wrong end?" The wedge is away from the truck, I would like it to split so I could toss into the truck. On the other hand, having the wedge at the pile (so to speak) seemed to be more practical unless you could back in beside the pile. The log lift came in quite handy as the stuff I was splitting was all butt ends, large diameter (24"-40") Another thing I noticed right off was the lift is too close to the tire and not close enough to the wedge, with the fixed wedge, those large splits either had to be held and slid back or drop and put back on the log lift. I would design things a little different for myself. I agree with the 4 way being too far back, the wood sort of goes off to the sides and doesn't split all the way.
Good luck with whichever unit you decide to buy!