I looked for a handle to improve the handling of the camera in combination with Tele / flash, because I have relatively large hands and it seems to me quite small by prolonged use while shooting in this use of the body.
The original MB-D12 I could test - he is in terms of processing (excluding gaps) and use of all batteries beyond doubt.
In addition, I think that in addition to the "sponsorship" of the brand Nikon possibly was placed more attention to the selection of materials, although it is not always understood by non-toxic materials, such as the recent shows of the recall at Canon. The price of 320, - I find exaggerated.
With regard to the processing of Vertax D12 I can not fault it - this is compared with a grip Meike MB-D200 and the elderly as well as the MB-D10 in my eyes much valent / robust or at least equivalent in the latter case. Nothing creaks, rattles, the thumbscrew firmly seated, the housing seals well against (perhaps a little too well).
A function in handle / Camera off / -er I can not confirm (as often described).
Only the smell when unpacking and closer inspection falls on something (minimally more than the MB-D12). This I know, however, from the automotive industry and other fields also. This should quickly disappear.
With regard to the intended use: clear recommendation. Tip: Watch the spot and get an idea itself.