Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Uneven set

This is a very uneven set. Heppner is a fine Lohengrin, one of the best around. Sweet, while not the Elsa of one's dream, is better than average. Leiferkus is mediocre and Marton downright bad. Rootering and Terfel are excellent, though. A mixed bag. Look elsewhere!