It just doesn't tamp hard enough.
Maybe this works for some people. But compared to my traditional tamp, it doesn't tamp the coffee as well as it should. It's really great at taking force away from your wrists and making for a significantly easier and gentler tamp experience. But the end result with the espresso, is simply that it is not tamped enough and it ends up affecting to brewing process because the coffee is just not tamped enough.