I can do it faster with a fillet knife than the demo guy does it with his gizmo, and I'm not half as fast as other people I know. It might be a good item for someone who rarely cleans perch or crappie. I'd put learning curve into filleting with a knife.
FWIW, a fast way to fillet and skin smallish fish is to make one smooth motion of cut from behind gills to just short of the tail, and do not cut the fillet free at the tail. The fast people never stop the blade motion but lift and flip with it so that the slab flips over onto the skin side, still attached to the body. Keep the knife moving the same direction and slide the blade between skin and meat. The skin connected to the body holds the fillet in place for skinning so there is no difficulty starting the blade between skin and meat.
The fast people use the tip of the blade to flip the skinned fillet into a tub. Even with stops between each of these steps, it is fast, smooth and easy. I usually slice off the ribs before flipping into the tub but some go back and do all of the ribs at once, later.