Re the blade rotating, I remember seeing a video somewhere (might even have been on one of the axe threads here??) of a guy who was an absolute beast, splitting a ridiculous amount of wood. He didn't have a fancy doo-dad like this thing - he angled the blade slightly at impact and it had exactly the same effect.

It's a poor craftsman who blames his tools, etc., and so on...

I'll see if I can track down that vid.