It is powerful enough at 28 cc in ideal conditions. If the soil is too wet the soil cakes up on the shield and you have to scrape it with a putty knife often. If the soil is clay and it's very dry that also bogs down the machine. Also the depth of the trench is adjustable, so the deeper you set it the slower your pace is.
Consider that the blade, (claw) is 3 inches wide and if placed on another machine you still lack the extra wide 5 inch shield and flap that throws the dirt forward and into the bed as you walk it backward. Working without the shield the blade would fling soil all over the place as well as the operator. It really moves quite a bit of soil as it trenches.