Summary: Lots of other mice we've had don't work immediatly when left on for a while, like overnight, you have to click it once or move it around alot before the pointer begins to move. This mouse works immediately, first motion. That may account for it needing a new *single* AAA every couple months.
Pros: Smooth, small, NO power up time, NO wake up from sleep time, one AAA.
Cons: 60 days battery life instead of many months when continuously on.
Summary: Very good price for the quality-Recommended.
Pros: Quality look and feel Response is good Rather easy to setup and start using
Cons: Not really con's but worth mentioning... This may sound funny :But: No clear indication on which way to install batteries. Slightly on the smaller side-but OK, it's for my wife and her tiny hands. :P