Instruct: Classify Amazon reviews into positive or negative sentiment
Query: great - but then....

Love this thing ergonomically, but the damn thing is unreliable. Left (and only really important button) on mouse is failing after just a few months. which makes it unusable. The keyboard also seems finicky despite putting in new batteries all the time. I am not a heavy user. Since they are coupled this would require me to buy the set all over again. NEver liked microsoft but thought i would give them a try.