motortola phones are garbage. sure razr maxx has great battery life and can last over a day, but the s4 will still last at least one day, fairly easily. i got used to charging my phone at night, and i think i'd probably do so, even if i had the maxx. also, i'd hold off on considering any moto phone until the new phones with google's imprint are released.
i say try out the gs4 if you're looking for a phone. feels nice, looks terrific, amazing screen, great camera features. it has a bit of everything.