There is probably a good supply of good log splitters out there. Now, what makes up a good log splitter. A good engine is necessary. Name brands like Honda, Kohler, etc. Any engine taken care of, will give reasonable good service. Hyd cyl, there is a bunch of them around. Supposedly, the welded cylinders are the best. Then again, what brand. There is the hyd pump, most are two stage, to give a fast speed, and then high pressure if needed. The rest is made up of steel, 4/6 bladed splitter wedge. valves, hoses, reservoir, and tires. If you look really good, you might find the best of the best in a splitter, if not, choose the better of the lot. If it splits wood in a timely manner, is all one could ask.
In choosing all the best features in a splitter, you will certainly pay for the upgrades.