who prize function over form
Then get a phone that has a OS that isn't bloated with eye candy, odd navigation menus, and constant connection for 'guessing your next request'... and crapware that runs in the background 100%.
There was a time not so long along phones ran for at least a day, and we're "zippy", now they're slow & buggy (I'm looking at you Android & WP) or last 6 hrs (iOS). And it's mainly from the OS being used.
Most of the functions I use on today's phone were available on a 2003 Palm Tungsten (email, cal, notes, sms, video, audio): and when I ran a Palm, it ran smoothly (though not as zippy as a 2013 phone), but lasted nearly a whole week before a need to charge. The latest "flagship" phones are so heavily bias to graphics and cloud gaming that kills everything else when is comes to usability.
Imagine a bare bones phone: web browser, video/audio player, sms and workable phone. 3000mah would go a long ways w/just that.
Want function over form: get a phone w/a efficient OS--yep, there's isn't one today.