i have an early 2013 15 rMBP and according to this knowledgeable article my machine gets 7 hours battery life. In reality, I am lucky to get 5. 4 is more like it. Haswell rMBPs claim 8 hours of battery life. Will I really get that, or will just get one more hour of battery life from what I get now? I fly to Switzerland from Boston 3-4 times a month and was soooo excited when Haswell came out as I could use it the entire flight, but now I'm skeptical. Thanks!