I am debating between a 17" or 15" macbook pro for college. The 1920x1200 res on the 17" looks pretty enticing, but I'm mainly concerned about the battery life and heat dissipation between the two. Does the 17" suffer from worse battery life (in the real world, not what apple has advertised) and does the 17" run cooler or at least feel cooler to touch because there is more room for the components?