I used this application on PowerBook G4 12-inch which has limited screen real estate and now I have a 15-inch MacBook Pro but still use SlimBattery meter since nowadays applications have grown their menubar presence so this applications helps. SlimBattery Monitor has many customization features like shape of the meter, warnings and what displays with battery monitor. The Apple Battery Status is good but takes too much space in the menubar and limited customization.