I am wondering if using an external monitor for a second display will impact battery performance on the new Air. I am planning to use an external monitor at work with an mDP to DVI connector. It will be used as a second display to watch stocks movement while the main MBA display will be used for my main work (web development). I am considering to purchase an MBA for the privilege of not carrying the charger when I go to work so I can use a slimmer bag. Also, does putting the MBA on sleep when transporting drain the battery quickly? Thanks.