Had one of the cal jet types motors running a few years ago. Disappointing. I was real happy when I got my 40 dollars back out. Experience only cost me an afternoon of time , fuel line and plug. The bottom casting must have been available to a couple different manufacturers and that impeller must be some standard off the shelf unit (?) cause I see them on different engines.
Novelty wise they are cool but even the huge benefit of not needing a 90 degree gear box (expense and power robbing) is not enough to make them useful. First trip thru the weeds will determine your love or hate.