I use a couple of different systems. Here are my thoughts on each:
1. Chef's Choice 120. I don't like this thing. It seems like it should work great. Three stages of sharpening. Foolproof guides for angle. Somehow though I cannot get the kitchen knives, hunting knives, or any other knife sharp. The form of the machine limits its usefulness. The knife blade needs to be long and thin enough to fit in the guides. Useless for thicker stuff like an ax, think bladed items like machetes, etc.
2. Lansky sharpener. Love it. I use the add-on mounting post screwed to a work bench. I sunk a nut into the workbench with epoxy so can just screw the mounting post in and out as needed to free up space on the bench. The mounting plate can be screwed down as well, but that left a mount on the otherwise flat surface of the bench. This thing sharpens just about anything. I don't use the diamond stones, as I am happy with the three that came with the system. Its not that good on really big or heavy stuff, like an ax but it will do it. It is time consuming, but it works every time.
3. oil/water stones/files. Used for more specialty things like mower blades, ax's, chisels, etc.
I am pretty sure I will end up with a Worksharp soon. Seems like it will do everything, of every size. At the same time, I rally don't need another gadget...or so my wife tells me!