Totally Necessary (2008-11-18)
If you own a D300/D700 and you shoot more than just the kids' soccer games, then you need this.

I use it with 8 NiMH AA Energizers because it seems more economical than the upgrade batter and plug (for me). Still shoots 8 fps with AAs.

If you shoot (semi)professionally, don't look around, don't buy the knock off, just hit "PURCHASE" then add overnight! You'll be glad you did.

Turns your D700 into a better camera than a D3 (2008-11-11)
Combine this with the EN-EL4 battery adapter and you basically have an updated D3. Works great, gives you the vertical grip extra shutter, selector dials and directional pad but doesn't add a ton of weight. Comes with battery adapters for AA bateries or another EN-el3 battery (the same as in the camera). I have taken pictures all day and still had plenty of battery left.

The only thing Nikon could do to improve this is to include the EN-EL4 battery adapter in the box.

Works Great (2008-11-02)
This is a great extension to your camera. Not only does it give you two different batteries life, it also works as a holder for your camera. It makes camera a little heavy but you can really stabilize the camera with one hand on the bottom side of camera.

Works great would recommend to anyone!

Get the right battery... (2008-10-31)
Maybe I was too eager, but I didn't realize the high-speed shutter advantage offered by this unit requires a different battery model - the EN-EL4.

I bought a second EN-EL3 (7.2v 1300mAh), which offers no boost in fps over the base unit. Only the EN-EL4 (11.1v 2000mAh) gives you the max fps.

Otherwise, I'm impressed with the quality and design.

Nikon MB-D10 Power Pack does the job. (2008-10-30)
Bought this power pack along with a new Nikon D700.

The pack is simple, and works just fine.