I never specifically checked the brightness settings on all 3 iPads I checked, but they all looked to be the same brightness and not excessive.
100% brightness is blinding so I don't think that's the case.
The difference in heat on the iPad 3 was astonishing...........crack some eggs on the back of the case and you'll be ready for breakfast in a few minutes. :D
Can't be good for the internals.
The iPad 4 was way cooler on the back.......not much warmer than the iPad 2.