Congratulations on the Pixel brip. Of my 3 grips for 3 cameras, only one is the Pixel, mounted on the D800.
I noticed you mentioned the MB-D11 was all magnesium which I guess was a slip of the tongue....er ah...fingers. It is plastic on the top half and cast metal on the bottom, so you were half right;>)
If the Pixel version for the D7000 is similar to the one I have for the D800, it has thicker and better coverage of the rubber than either of my others or a MB-D11. It has a better tactile feel of the grip area, sides and bottom than the camera does maybe because of the thicker textured rubber used. My grips have not suffered from the common Nikon grip rubber problem of swelling up and coming off the body. Skin chemistry determines if that happens but so far the rubber on all the after market grips I have have held up better than the Nikon rubber grip inserts.
Concerning battery capacity, a grip on the D7000 does not need another battery since the D7000 is so frugal with battery juice but other models certainly benefit from it, or when shooting video.
Stan
St Petersburg Russia

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