Samsung Galaxy Note 2 sports a very premium finish and uses better plastics than the Galaxy S3 but there are some people (not me) that like to add some metal to their phone by using a metal battery cover. This immediately adds some more class to the design. These cases can be bought from amazon or ebay and cost somewhere between $8-$15.
I once bought it for my first generation Galaxy Note and immediately noticed a drop in signal strength which was evident as metal blocks signals. Another thing not to like about it is that they do not have NFC connectors inside. Official Galaxy Note 2 flip cover has it which makes it one of the few cases that have connections for NFC.