From my understanding: The i7 runs approx 11%-15% faster than the top end i5. The problem is, it is slightly hotter. The fans will then run faster so that's more noise. The battery life is then shorter. When the i7 runs non-intensive programs, (Word, Safari, iTunes), the overall noise, heat, battery life and performance experiences are similar, if not identical to the i5. When demanding programs run, (Games, audio apps, video apps etc.) the i7 is a hotter, uncomfortable computing experience with more fan noise than the i5, with a shorter battery time. However, this is where the i7 shows it's performance advantages over the i5. Correct? Please note: I have done a lot of reading on these forums before making these conclusions.