I have one for my D70 as well.
Raskill basically mentioned most of the important feature, larger (much comfy) grip, the acceptable vertical release, and the battery life.
About the battery door, its very easy to remove and to put it back, so its not a problem.
Other point in concerns for me about the grip is that it only grab hold of the battery insert, and tripod mount on the camera, leaving the left side of it unattached and no hard conact to the camera, it will wobble a little bit if you mount it on tripod with the grip's tripod socket.
The tripod socket iself is not perfectly aligned with the one on camera (Raskill, can you check if this applies to yours as well?). Doing panoramas can be a bit of problem when it comes to stitching up.
Other than those little issues, its a great addition to the camera, specially the 2x battery inside and extra grip + weight + size. Handling and holding the camera is much a pleasure despite the weight.