Instruct: Classify a given Amazon review as either positive or negative.
Query: Poor Performance for Birkenstock!

These things are basically a greatly overpriced Dr. Scholl's pad. At nearly $30 they are just a foam, latex pad with a sort of Birkenstock arch support. If you want a Birkenstock insole you'll have to cough up the bucks to get one of their hard insoles because this will not do squat!