I've narrowed my decision for 13" rMBP vs 15" rMBP down to the need for a good battery. (Duo vs Quad is irrelevant to my needs as is the 13" MBA) Two reviews are miles apart on battery life tests: MACWORLD LAPTOPMAG The 15" seems to surpass the threshold where the battery life surpasses the pixels it pushes via its larger battery size. The 15" pushes more pixels and yields 30 minutes more battery life. In other words, Apple should have made the 13" rMBP battery even larger just to match the 15" performance. Anyone seeing 13" rMBP better performance than the paltry 4:40 in real world usage (although rigorous) or better than 15" rMBP?