Instruct: Classify the given review into positive or negative sentiment.
Query: marginal at best

we purchased this toaster due to the good reputation of the brand. it is only about a year old and already the burners are failing which leads to extraordinarily uneven toasting on two sides of the bread. the bagel feature is nice, but you have to constantly adjust the "darkness" because of the uneven toasting. extremely disappointed that this toaster does not allow you to use all four slots at the same time!