D800 Battery Pack

Canceled my March 17 order with b&h for a D800. Received the D800 yesterday from Ritz Camera, Naples, FL after about 10 days from day of ordering. Battery pack came today from b&h, very different from my D80 battery pack. The D80 battery pack holds two Li batteries and both are accessible without removing the battery pack from the camera. The D800 battery pack only holds one Li battery and the pack must be removed to retrieve the other battery in the camera. What is the advantage of the D800 battery pack?? Love the camera......very different from the D80!!!