Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Poor quality control

I've been a Riedel user for many years, including a set of the Sommelier series. These Ouverture Magnums have been our everyday wine glasses, and when some break I order more. The most recent set was very disappointing, with visible striations on the rim edges from substandard "polishing" on all four glasses, and you can feel the roughness when you run your fingernail along it. So think twice or three times before you buy, and recognize that you get what you pay for.