There is another question of performance. If the international has 2 hrs less screen time but able to perform tasks twice faster as a result of having 2 extra cores then its not as straight forward as it first seems. Antutu already showed that the one x is up over 60% faster than the xl. This could translate into faster loading of applications, webpages and applications that takes significantly less time to process. In the end you may not need as much screen time on the one x compared to the xl.
Faster in what?