If I understand it correctly, you just cannot void the law of physics (respectively the present technology of producing batteries); if the original battery is 1320 mAh and you want to to have a 2400 mAh battery then it can only be cca. twice as big.

Of course if somebody will innovate, develop, introduce and use some new kind of technology of producing batteries, they could also get smaller; but at moment we are not there yet.

... I could be wrong though and this MP batteries are just so big because of the cheap production using old technology