We should probably move this to Maintenance where we discusss sharpening.
Let me tell you, I started sharpening seriously a few years ago, when I got a Sharpmaker. It's a great system, the instructions that come with it are a revelation in themselves, and I got consistent results on all kinds of knives. Also scissors, potato peelers, and nailclippers!
I also learned to sharpen. It is more understanding than anything else, you have to know what goes on at the edge of the knife that makes it different kinds of sharp. Working with the Sharpmaker teaches you about this as you use it.
So tonight, I dug out a tiny stainless steel cleaver from the back of the utensil drawer. Cheap, barely useful, came with a cheese collection on a small cutting board years ago. Never took much of an edge.
I sharpened it on a flat fine diamond benchstone to a convex edge: something I never knew existed until recently, and here I was using a marginally appropriate medium and achieving impressive results. It's not the tools, it's the technique, the knowledge you develop.
I was thinking about the Duckfoot myself. But I've got other tools that are just as portable and I know how to use them already. I'm sure it's worth the money. Sal Glesser began Spyderco by marketing the Sharpmaker; the knives came later. He knows sharpening equipment. I'm not sure the Duckfoot is as good a way to learn to sharpen as the Sharpmaker, though.