Instruct: Classify Amazon reviews into positive or negative sentiment
Query: minimal knife sharpener

What amazes me about all of these 5 star reviews is that there is little warning that what is touted as a knife sharpener is truly minimal. If you are looking for a robust knife sharpener that works electrically with something like carborundam wheels and can handle serrated blades; this is not for you. You may have guessed this by the price. If you are looking for only a can opener, then all 5 star reviews have meaning.