I don't really use my battery "that much" in the first place, It's almost always plugged in to something, computer, wall, cigarette lighter (that's what they are there for right?) The only time I don't use it that way is running. I've gotten 12 hrs of music out of it before it shut me down (not plugged in), this is pretty good in my book. I can see how on a camping trip it could be a bummer, but I guess that is where the belkin auxiliary battery pack that takes regular batteries comes in.
it gets in my book. My one recommendation, get the biggest you can affored, you'd be surprised how much music you really have. I've filled up my 10 g easily.