If one is willing to accept a few shortcomings ...

... It is not so bad.
But the reasons why I sent him back on the way back:
- The steering wheels (front and rear) feel slippery and slightly reluctant to (quite different from the camera) - but they work correctly
- The control wheels do not follow the 100% setting in the camera. If you have moved there, the directions, the BG acts possibly different from the camera when you rotate and served with their buttons.
- The D-pad is very smooth and has often times "cheated" when I do, that multiple operations performed
- The leather trim is also different from that of Nikon - somehow smoother.
- There is always (even after multiple re-start) a gap between camera and BG and therefore a game of twists and wobbling.

- But what really is super: the release button is very clear in its two levels - focusing and tripping. That's almost better than on the camera itself and a bissl defined as at the same time ordered Vertax BG for 30 euros more.
- Also no other electronic failure. Also, the AF-I / AF-L could be as BG-button specially programmed in the D7100 menu. Very nice, actually.

I was ready to keep the BG because he is simply unbeatably cheap. But the Vertax is with regard to the steering wheels and leather trim, significantly more pleasant and much closer to the original Nikon (frankly, hardly any difference, except that the control wheels click louder), sits tight and makes it for still only 1/4 of the price of the Nikon original in my opinion a super good job.

I give 3 points (satisfactory), because you could say for the money quite "Okay, for the few times where I'm used to, and for the money not bad". But I myself am going to carry the BG quite longer and more durable on the D7100. There should already be voiced, precisely fitting and stable.