Instruct: Classify Amazon reviews into positive or negative sentiment
Query: useful, but be careful of the bottom

I got one because Alton Brown uses one, and its great to have on the table. I wish it had rubber feet, though, because its just bare metal at the bottom which will scratch your tabletop. As a fix I went to a hardware store, bought a sheet of cork, and glued it on. However it really should come with something to protect the surface it sits on.