My favorite is the 2nd one. It's fast, strong enough for the job, only moves when you want to, can be hooked to several types of different motors (gas, electric, whaterwheel, tractor PTO, etc), and seems to be simple enough to fix in case it breaks.
I remember a video of an old man that was hand splitting wood and had surrounded his home with firewood. The firewood was serving as a windbreak and insulation. So much dedication in all of that.
That grey one with the buzz saw and splitter built in one, is one of the few that are substatially faster than a couple guys with axes AND MUCH less labour intensive ... if I was still heating mainlt with wood I'd make up that one ..
I like the rack and pinion one but I'd like to know how they get the gear teeth to engage smoothly without skipping, chattering, or grinding.
The last machine with higher working position would be great, mostly silent and effective machine
And I’m still the old fashioned way, in the forest I saw vylezhnik, oak, ash, acacia, with a home-made 80 cm hacksaw, logs up to 45 cm in diameter, and I roll home 2-3 pieces on a bicycle. At home, I saw Makita with a chain saw, and I split it with a cleaver. 15 m³ per year.