well.. current phones can have long battery life if used only as phones, managed to get my Galaxy S3 to have a 6 day battery life... but only used it on phone calls only. Usually i get 2-3 days of life time with ease ..but if i start heavy internet use half a day and it`s dead.
Any smartphone can get decent battery life: turn the screen down when not using it, run it on the cell network (turn off WiFi), and close any non-essential apps with task manager. Of course, if you have a quad-core processor, LTE, and a big screen (especially LCD) it's going to use a lot of power. That's the nature of the beast.
What I would like to see is a 1280x720 screen and 16GB storage at a reasonable price (obviously higher than for the E4, but not like $100 more). I don't care about extremely high resolution - seriously, 1440p is bad enough, now they're even going 4K.
Resolution has diminishing returns, so getting to a medium resolution like 720p is worth it, beyond that it has less of a benefit and hurts battery life and performance.