Jim, I never ordered the MB-D12 because of the expense, but have recently seen that Phottix make a magnesium grip for the D800. I have used other Phottix equipment and I feel they are a relatively good company. I have never been very fond of aftermarket grips (especially when someone complained about the Meike version breaking while installed on the D800 and being impossible to remove without disassembling the camera), but I took the chance on the Phottix Mag version. I ordered it but have yet to receive it (something about a religious holiday). When I get it I will examine it to ensure that there is an escape route from internal failure while installed. Once I have any significant assessment to report, I may post such information (if I remember).