I have both 3pt hitch / tractor-powered splitter and a self-contained one which I recently acquired. While the OP fully understands and has articulated his infrequent need to use a splitter, for others in the future who might come along and read this thread I'll share my thoughts.
Having used the tractor-powered splitter with a MF-135 as the source of hydraulic pressure, I have to say I have never been happy with this situation. The diesel engine on the MF135 is one of the sweetest-running diesels in the tractor world. Still, it's surprising just how much noise it makes running at a fairly constant ~2000RPM to power the splitter. I actually found it would grate on my nerves when I otherwise love the sound of that tractor. Weird, but true.
I like being able to just back the splitter up to the pile of blocks and split right there, but it also means the tractor is RIGHT THERE, too. One has to be ready to work around the tractor.
The self-contained splitter is, for my methodology, just much easier to use. It's considerably faster, quieter and is much smaller so easier to work around. Yes, I push it by hand to get it into position to work, but that's not such a big deal.
The biggest complaint I have with both my splitters is that they both have the solid flat "pusher" mounted to the hydraulic ram and the "splitting wedge" hard mounted to the stationary rail. My father's self-contained splitter has the wedge on the end of the hydraulic ram, a configuration I much prefer as the piece of wood being split doesn't move away from you but rather stays right where you put it.