I was initially very skeptical, but after I the first few apples and cucumbers peeled away the shell did, I was disabused.
The device is very comfortable to hold, the button is easily accessible. The knife is extremely sharp and the cap holds well on the device.
The device does its job very well, but it's for my taste a bit too loud. One can thus very accurately separate the shell from the fruit / vegetables, at the first attempt the result looked better than with a conventional peeler, but we go with the battery-free paring knife quickly.
Somewhere under the line a good development and a cool kitchen gadget. However, I do not think that it will prevail against the normal paring knife.