I'm thinking of buying the 5Diii, and getting the vertical grip. Does anybody have experience with 3rd party vertical grips for the 5D, 5Dii or 5Diii? There is a large difference in price, and while it shouldn't be rocket science to make a 3rd party version, how well do they work? And would the usual L-Brackets (Kirk, Wimberley, RRS, etc.) work with them?
The Canon version for the 5Diii is about $350 at several sources, and if history predicts the future, there will be 3rd party versions at $100 or less.