There's no way 3.5" is the "sweet spot" these days. Maybe for primary school students, at most. Otherwise kids want phones with larger screens these days, too.

There's no way 3.5" is the "sweet spot" these days. Maybe for primary school students, at most. Otherwise kids want phones with larger screens these days, too. I'd say 4.3" should be the minimum for just about anyone. Phones are more compact than the days of iPhone 1, and most of them are 16:9 now, which would make 3.5" way too cramped for using the keyboard.