I have tried my MB-100 on three d100s. The fit was great on two but on the third (mine) it definitely was not a flush fit. I think this has to do with inconsistencies in the d100 dimemsions. There is a looseness on the shutter release side of the grip and the separation is very noticeable when holding the camera vertically. I could hear the contact pins squeaking as I handled the camera. I remedied this by using some electrical tape to wedge and cushion the contact between the camera and the mb100. I layered the tape (about 3 deep)until I got the right thickness and applied the tape on the opposite end of the grip to wedge the shutter side closer to the body. This also adds a little cushion to the contact without sacrificing stability. With a hard plastic to plastic contact, the fit is not stable if the dimensions of the camera and grip are not perfect. Anyway, the contact is stable enough now to use the grip on a tripod mount. I also noticed that the door to the memory card is loose and rattles when I handle the camera. Again I used a carefully placed small piece of electrical tape to fix this. I guess not all Nikons are created equal. I just hope I don't have to resort to duct tape!!