I rather like the idea. I know I've seen it posted here that the best way to split wood is to let the axe fall to one side, but it looks like the Finns have taken it a step further and designed an axe specifically for that purpose. It only penetrates the wood a little bit, and then all the rest of the momentum is turned sideways to push apart the two pieces.
It seems a very simple design that might save a bit of work. (Although from the videos on Youtube their claim that it never gets stuck in the wood isn't 100% accurate)
The operational video of this ax is well worth watching for ANYONE who heats and/or cooks with wood.
I've always felt a mechanical wood splitter is a bit impractical for anyone of average strength able to use a good ax.
The key to this Finn's work may not be the ax but the TIRE. Most of the labor expended in wood splitting is repeated bending over and resetting the log for another swing. The use of a tire to hold the wood in place for "nothing but swinging the ax" will eliminate a very substantial portion of labor.
For you long time wood burners who process their own wood, take a look and see what you think. I've heated and cooked with wood for several decades and the biggest breakthrough for me in that time was the discovery of the tire.
The ax might be the real deal too ... those Finlanders are really smart people, especially when it comes to forest work. Frankly, I'll stick with my own ax, but highly recommend the tire concept.
If one compares the speed of the ax and tire method with a mechanical wood splitter, I would guess the hand method to be at least twice as fast.
One more thing if you watch the video... I'd be willing to bet the ax man is working with frozen wood. Best time for splitting is when the temp is below freezing for a few hours. Wood splits so much more easily when frozen.