This sharpener is about what I expected. I was looking for something to take along hunting and camping so I could sharpen my knife when needed (skinning a deer, etc.). An electric sharpener was out of the question, and I've used diamond stones before, and they aren't feasible for "in situ" sharpening. This sharpener works great for hunting-sized and larger knives (4" blade and longer).
I let a "friend" use my hunting knife and he mistook it for a hatchet and took some chips out of the edge trying to hack thru a deer pelvis... After 7-8 swipes with this sharpener, the edge was definitely more uniform, and the chips are definitely smoothed out.
My one gripe is that you're supposed to push the knife down thru the spring fingers and then pull back. After a few swipes, you end up with the finger pattern showing up on the knife edge. I can't tell that it hurts the knife at all, but it is slightly disconcerting.
Obviously, outdoor knives are stout cutlery and are meant for spirited and reliable use (aside from hacking at deer pelvis'), but I would definitely not recommend this for kitchen cutlery.