Before taking this permanently down to the allotment for sharpening my hoe, axe and the other garden tools mentioned, I thought I'd try it on the old, blunt kitchen knives. It was a bit brutal, but boy, are they sharp now! Using one of the newly sharpened knives, I just tried to cut a pack of coke cans free from their plastic wrapping and accidentally punctured one of the metal cans! The knife was much sharper than I thought.
I said "brutal" because it did leave the sides of the knives a bit scratched. Not a problem for old kitchen knives, but beware before you sharpen your finest knives... now for my axe and my hoe.
For sheer sharpening power and the fact that the manufacturers guarantee it "forever", I'll give it Five. Make sure you buy it for the right purpose.