Like others here, I keep wifi off while I'm reading and only turn it on to update my Omnivore articles or update my saved position in a book (using Kindle or Kobo apps).
I have no idea how the battery holds up for the people who are trying to use it as a phone (ie using it a lot for browsing or chatting and other battery-heavy apps).
I just wanted a phone sized eReader that could let me install apps other than just a bookstorr. The Palma fits that bill wonderfully.