Foo: Got my new 2000mAh extended battery this week and have managed to get 12 hours life each day, with about 20% remaining. I'm running stock ICS 4.0.3.
Am using streaming music over 3G for about an hour each day, but fairly light phone usage during the day (couple of calls/dozen sms messages/little web browsing).
Guess I'm getting 2 - 3 hours extra usage versus 1650mAh battery. Well worth the investment, especially at the price.
I could easily get 36 hours from my 1650mah battery with GB!