Android 6.0 really ups the game with formatting SD card as internal storage. Those with a measily 8GB phone like the 2nd gen Moto G will benefit. The Nexus phones do not have SD cards, the Moto G seems to strike a sweet spot.
Battery life takes a giant leap with two days perfectly possible if you turn your phone off at night & use Hermit for Facebook. Greenify has an aggressive doze feature which should help in conjunction with Twilight app. Your mileage may vary but you could discover that an SD card r/w speed upgrade is needed.