We've got a homemade hydraulic splitter as well, Honda engine. We have a wood water furnace and go through a good amount of wood. The splitter is a monster and will go through just about anything...although some knotty stringy pine could be a pain. I'm not sure about the kinetic splitters. There is no doubt they move fast, but some of their cited advertisements are compared against some of the smallest, slowest hydraulics. I can't say anything bad, or good, about them....I just don't have any experience. I will say that I split a decent amount of wood, some pretty large. I've never been disappointing with my hydraulic splitter.
Smurf, seeing the video of that splitter scares me too. I'm very methodical and purposeful when splitting. There's just too much power there...to accelerate and get thing moving that fast isn't a positive to me at all.
For the record...the guy in the video is splitting some pretty small stuff!