No problem with this iMac i7 and the Wireless keyboard though (this iMac was made in March 2010 according to the serial), it's battery efficient, only using 7% of the alkaline per 16 days and it's always ON. OS X warns you to change it when it reaches 10%. The battery only has 7% and I had removed the batteries for fear of leaking if it discharged too deeply. The iMac's sleep mode for everything is ON) because other wireless brands also have laser but no multi-touch sensors like the Magic's.
The multi-touch sensor mostly I think is the one that drains the battery so quickly (I've only used my iMac for 16 days at about 8 to 12 hours a day. But the Magic Mouse seems to drain battery too fast I think because the multi-touch and laser at the bottoms needs to be constantly ON a little so that it immediately knows if you're using it. The low profile at the front is also very ergonomic coz' your hand is as close to its natural position as possible using the comfortable palm grip style with the right button feature OFF and if you're versed with the keyboard shortcuts (right clicking using the Control key is faster)- see Razer for grip styles.
The Magic Mouse is great especially with scrolling and moving between pages quickly.
