Took a peek at my Bionic's extended battery, 2760mh. And the GS4 will be 2660mh. Hmmm. Depending how hungry the battery consumption for the GS4 I may just stick with the stock battery haha.
If it does prove to be a thirsty bugger, then just maybe I'll consider that zero lemon battery. Though that oversized juice box for a battery must be huge.