MB-D14 Multi Battery Power Pack

This is the best addition to my D610 since Nikkor lenses. The extra battery life is important to me for longer shooting times and the vertical shooting hold is ideal.

I bought this new with the D610, and a second EN-EL15 battery.
It has a solid feel when connected to the body. Feels good in the hand. And the controls are well placed. No awkward reaching for controls. I especially appreciate the location, and functionality of the selector control.
Two faults. (At least in my mind)
1) It only holds one battery. I shot almost exclusively in RAW mode. And when shooting, for most of the day. Would prefer two batteries in the grip. As it stands. To use two batteries. One must be in the body. It is a nuisance to have to remove the grip to access the second battery in the body. Also, the optional AA battery holder is not very effective, in my mind. Just give me two EN-EL15, in the grip. If someone at Nikon actually reads these reviews. Two batteries in the grip would be nice.
2) This is not a performance issue. But, certainly, it does get under my skin. Something shakes inside. Either the battery, or the battery holder. I hear it. I feel it. Drives me nuts.

On one hand, this thing is incredibly solid and great for people with big hands. The magnesium alloy body definitely made the D600 feel more solid (unlike the very flexible 3rd party plastic grips..although they also cost 1/3 the price), but what prevented a higher overall review is that the rubber started to stretch and come off within weeks of the warranty ending