Mine is atrocious, and one of my other guinea pigs is even worse off. He gets 3 hours from a full charge using maps, 3.5 hours if plugged into a (0.5A) car power adapter.
In both cases, it was fine on 5.1.1 and beta1, and tanked on beta2. 3 seems to be a hair worse, battery-wise, than 2, though overall it sucks less.