I borrowed my neighbor's 3 point splitter when I was trying to find out what worked best for me. My tractor is a New Holland TC33D - a compact tractor and I believe the hydraulics have about 2,000 psi and 10 gpm. The splitter was horribly slow on my tractor and because of the low pressure it got stuck often. There were no "dislodger" features and it required a sledge hammer every time a log got stuck and on some big Hickory I was splitting this was a real effort. It also was a horizontal only unit and it stuck straight back from the tractor and had the splitter wedge on the end of the beam and the flat push plate on the cylinder. When I would wrestle a huge round onto the beam and split it - the round would then be pushed off the beam and fall onto the ground - which would then require that I pick the darn thing up again and get it back onto the splitter beam.
It was very nice of my neighbor to loan me his splitter - as it taught me a lot about what I wanted in a splitter. I think you should go rent or borrow a splitter or two before you buy one so you can find out what works best for you - rent one that is only horizontal, then another one that is horizonal/vertical.
For my own use the following works out best:
1) I like the horizontal/vertical option - if the rounds get horribly big then I can set the splitter upright and wrestle the rounds on the ground. After the wood is split you only need to reposition the big round on the ground and split again until the round is gone.
2) I like the wedge being mounted to the cylinder and a log cradle on the beam to hold the split pieces while you work. This allows the round to remain stationary while you split and you can stand in one place. On the other kind where the splitter wedge is mounted on the end of the rail and it requires that you retrieve the round and bring it back to split it again. (This seems to be the preferred system for large commercial splitters with wedges that split multiple pieces simultaneously).
3) For my tractor with the small hydraulic unit the PTO driven pump would work best - as my tractor did not drive the cylinder quick or hard enough. I ended up getting a splitter with an engine, a log cradle, and a dislodger.
4) For me the engine being part of the splitter was a big improvement. It is louder than my tractor - however my tractor is usually hooked up to the trailer for collecting wood and I would need to keep switching from having the trailer/splitter connected while gathering and splitting wood. I also believe the resale value of the splitter will be higher as the market will be bigger - although I can't see that I will need to sell my splitter anytime soon (although my widow might!).
I really think my system works well for me - I cut my logs to 24" length and haul them in my trailer with the large rounds seperate from the pieces that don't need splitting. I then put the log splitter next to my woodshed and back the loaded trailer up next to the splitter. I unload and stack everything that doesn't need split, and then start up the splitter. As I unload the big rounds I pick them up from the trailer and and set them on the beam, then split the rounds, then pick them up and stack them. I never have to bend over unless I drop one or I am starting a new row of wood in the woodshed (Or if the round is so big I have to roll it off the trailer and split vertically).
