I ran all of my filet knives through the ken onion the other night, they were sharp as new in no time flat. I havnt tried any important knives yet though.
Got one not too long ago, It works pretty good and is relatively fast. It gives you a nice convex edge which seems to work good. For my higher carbide knives like M390, and S30V I use my Edge Pro Apex sharpener. For EDC and hunting knives I use the Lansky and for my filet knives I put it on the 18-20 deg setting.