Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Looks sharp, works dull.

Chicago Cutlery has been a good name over the years, but this sharpener does not live up to the quality of their knives. It might be fine if you already have a good edge, but if you are starting from a dull blade, you'll need an Accusharp sharpener. That's the one you'll see in the hands of chefs and butchers.