Hey I'm about to take the plunge and buy the new MBA 11 Ultimate 2011 but still unsure about battery performance ? I need 4 solid hours of battery life on one full charge - will use internet 3G Tethering/WIFI where available for 1 hour, on and off Pages and Numbers for 3 hours and some PDF reading - typing pretty much for 3 of the 4 hours in Pages and Numbers. I really like the portability and extra small size of the MBA 11 compared to the MBA 13 ( I own the MBA 13 Ultimate 2010, which I will sell to fund part of my new MBA ) as I also have an iPad 2 and iPhone 4 on me and some HEAVY books. I like the MBA 11 Ultimate now that you can get it with the same powerful BTO CPU as the MBA 13 Ultimate. Also the desk space at university is limited, speaking in favour of the MBA 11 instead of the slightly bigger MBA 13. My one and only concern is battery performance - I need 4 SOLID hours of battery on one full charge !! So what do you say ??