I used to have rev C MBA, the battery is like 3 hours surfing internet only. The old spec was 40wh for the battery. New MBA, CPU is the same, graphic is better, so consumes more or at least same battery than the older model? And the new battery is 50wh, only 25% more than the older one. So, new battery time, less than 4 hours?! I hope I am wrong, I'd like to see at least 5-6 hours if not 7.