I still wouldn’t correlate that to screen size. Personally, I returned the iPhone 5 in favor of the smaller screened iPhone 4s, but I’m the exception (and would love to have one with lte that size).
I think there has been a major shift from feature phone to smartphone and the iphones popularity make it an appealing choice to first time buyers. The iphone 4 and 4s are just cheaper so they capture people just hoping on the smartphone bandwagon. I’ve noticed an absurd amount of people on the subways with iphone 4 bodied devices. It’s like the new razr.
I’ve left mine off. I found the lights distracting. I used to look for lights instead of looking for the apps icon. Now I just go straight to the app and don’t think about weather it’s running or not. I still use command tab to do a check every once in a while that not to many apps are running though.