The battery life of my Pandigital White is about 5-6 hours. I use it strictly for reading, wifi off.
I use it every day and love it, but for me it is a single-purpose device: it is my bedtime reader. That is the one area where LCD screen devices are fantastic. I sleep in a bedroom with a baby and wife. A clip-on light for a book or e-ink reader keeps the kiddo up and makes the missus toss and turn.
But the Pandigital running either coolreader or aldiko (I use both) works great. Not only do they have night modes, but you can make the text gray instead of white (which is too bright for me). I can read for an hour perfectly well and not disturb anyone.
I generally have to charge it every 5 days or so. No problem at all.
I've never really used it for anything else. It may be a Yugo, but it gets me where I need to go and I don't see upgrading until the wheels fall off it. (Doesn't hurt that I got it for 60 bucks brand new during the Kohl's clearance sale).