The original handle MB-D14 'extended' the camera really fit and fits perfectly the camera is decidedly better in the hand.
The original conveyed (compared to Minadax handle) a clear wertigeren impression with regard to processing, stability and controls. In particular, the adjusting wheels are much grip and run full and precise as on the camera itself.
A Nikon D600 is designed for 7-9 volts of the MB-D14 therefore has a battery tray for six AA batteries, so max. 9 volts (the battery has 7 volts).
The Minadax Grip comes with a battery carrier for eight (yes, 8 !!!!!!!!) AA batteries with 12 volts? !! (If the Minadax handle with eight batteries is D600-killer, I'd rather have not tried).
Operated with battery is the Minadax (certainly no 'magnesium') a decent and reasonably priced alternative to the original.
My choice was still clearly on the more perfect original Nikon MB-D14.