smartphones: not as responsive to touch as you'd like, typing is still annoying and its easy to type the wrong words or type things that aren't even words at all. things like s5 is too big for a thumb to stretch across comfortably to do whatever.
flipphones: If I get a call or need to call i flip with the thumb without even looking at it, punch in the numbers without looking and 100% sure to get the numbers and buttons pressed as desired unlike smartphone, and press call without looking. Put phone up to ear.
smartphones are nice for games and net browsing on the go if you gotta check on something but i still prefer laptops for typing. must faster. smartphone zigzagging the finger is way too lazy and people don't get to develop typing skills.