I have the i7 1.8Ghz MBA. Ive been using it for about a week and I'm finding the battery is not as great as id like. Im getting approx. 5 hours, sometimes a little more and sometimes a little less. I went for the 1.8ghz more as future proofing no brainer decision as i don't need the extra speed right now and i really want to keep this MBA for as long as possible. I don't want to think about upgrading for a good few years (tired of it). I was hoping for 6-7 hours consistently regardless as i don't do anything high end - just browsing & text work. I do switch quick between apps with expose mission control etc a bit. Anyway, is there any difference between i5 & i7 processor interms of battery mileage. Im not going to do anything or swap my mba (even though i have 1 more week to do so) I'm just curious as to whether its me or the processor or apples over estimate. Does the 1.8Ghz drink more juice? I am turning off the backlit more when necessary. Any stats on how much per hour that eats? Thanks.