I've used almost everything listed above, still have 3 or 4 of them in a drawer somewhere, and always come back to good, old-fashioned whetstones - but have now added angle guides. For folders or good kitchen knives or hunters/skinners, they all come out razor sharp if I do my part.
For near idiot-proof sharpening that doesn't grind away too much blade, there is no better option in that price range.
Amazon link
For near idiot-proof sharpening that doesn't grind away too much blade, there is no better option in that price range.
Amazon link