I have the Mophie too and I love it. It's one of the best cases made Mophie. If your going to get a battery case I would def. Take a look at the Mophie case at the store.
I also have to agree, it's my 1st battery case ever & I am very happy w/its performance, function, feel & looks. Read the reviews you just can't go wrong w/the Mophie for the iP4
its not that bad. guess im used to my old windowsmobile phone. battery life means everything to me since its my business phone. thanks for the insight guys