Kinetics are only faster if you have wood that's easier to split, put a big crotch or tough wood to split on one, and the fun begins.
At the "Sawmill EXPO" this year in Ohio, they had a "splitter", firewood processor competition,
There was a bam bam (Super Split) next to a hydraulic with a 4-way wedge, both had similar wood and a helper. The hydraulic got done with it's pile a fair amount faster than the bam bam. Why ?, because the wood they had there to split, had some tougher wood and some crotches.
Here's a pict. of how much wood the SS had left, when the Timber Wolf was done splitting,
I like Super Splits and the like, but it just isn't true that they are faster than the better hydraulic splitters, at least in the kind of wood I split.
BTW, the ONLY two brands of bam bams I'd even consider are Super Split and Split Second...
SR