Reason: The bulk it adds and thickness to the phone makes it impossible to use with any accessory. So if you want the car dock or soon to be out home multimedia dock, do not waste your money on the extended battery. The 2 docks were not designed for it and cannot be modified to use with them...
Lastly, all cases until some third party designs something will not work either....
The Question: Why make accessories that are oem and incompatible with one another... thanks verizon and htc for ruining my extended battery party in a world where all accessories work together...
