Before 4.3.2, in standby mode for 12 hours on iPhone 3GS, I would show 60%. today after 12 hours in standby mode, it showed 75%. Pretty good increase.
Mind you this is with only a couple of apps with notifications and all apps closed, nothing in the dock. Have not had a chance to test the iPad, but hopefully it's the same sort of increase of 10% or better.