I thought those splitters were a great Idea when I first saw them, but the more and more I split with our conventional style, the less I think that style would actually be practical.
First, we cut a lot of large diameter stuff, and a splitter capable of vertical is a MUST for me.
Second, a lot of the easier splitting stuff like red oak, ash, cherry, etc, the wedge only needs to go 6" into a 20 " peice of wood to split it. Thus with one of those you would be either reversing it like a conventional splitter, or waiting on it to complete the other 14" of its stroke before splitting again.
I have also not seen or know of a good way to put a 4 or 6 way wedge on one of these. So that would also reduce productivity vs having a slip in 4 way you could drop on in 2 seconds when you get a peice the right size.
Lastly, if you are splitting by yourself with a conventional splitter, 99.99% of the time the splitter will have already completed its return stroke before you are even ready with your next peice.
The only time I could see one of these being advantagous in MY situation would be when splitting tough stuff like american elm. Where you have to run the wedge all the way through most of the time anyway and is just too tough to use a 4 way with good results.
But to each his own. This is just my:2cents: