True. I won't argue that better, faster devices will get more usage. For the day that I owned a 5s, it was incredibly fast. There is one more thing I forgot, ho

True. I won't argue that better, faster devices will get more usage. For the day that I owned a 5s, it was incredibly fast. There is one more thing I forgot, however -- there might also be a bias for the 5s in that early adopters (and those who upgrade every year) could be more likely to both own the 5s and have been trained by past iPhones to use as much data as they want. Those who stick with older phones might not use them as often off wi-fi. (Where "as often" is still within reach.) Who knows, though. Perhaps the difference is that the iPhone 5S is easier to unlock, or supports LTE in more places. I'm sick of guessing, at this point. :)