Rolling knife sharpeners promise make it easier to achieve a razor-sharp edge on your blades, but do they actually deliver?

After less than five minutes of running it through all three stages of the Trizor XV, it was shaving a path through the hair on the back of my hand — something it couldn't do right out of the box.

Basically, you invert the rod and hold it by the handle with your non-dominant hand ... to use for honing a knife between sharpenings. Tumbler Rolling Manual Knife Sharpener ($130): I like ...