The about $180 Really Right Stuff L-Bracket for Nikon D850 waits in my camera bag, ready to go onto my Nikon D850 when it arrives, and stay there permanently, just as with my Nikon D810. Fit and finish are superb as usual, and one benefit perhaps not readily noted is that the L bracket reduces wear and tear on the camera too.
As of 20 September 2017, Really Right Stuff says:
We are in full-swing production and cranking them out as fast as we can. The first batch should be shipping out this week, depending on what time we get them in from our supplier. However, we have many back-orders for the plate and we are shipping them out in the same order that we received the preorders. If someone places a pre-order today, it could be as much as few weeks before it will be fulfilled.
Its design includes the nice touch of a built-in allen wrench in the bottom plate, so one can take it off or put it on quickly, without having to remember to carry an allen wrench.
Like all L brackets, the dovetail allows the camera to be instantly mounted into a compatible clamp in either portrait or landscape mode—no flopping the tripod head.
I like L brackets for another reason: the bottom and left side of the camera are protected from scrapes and dings. I almost never take the L bracket off my cameras. Most models allow just the base plate portion, in case the “L” is not desired for some reason, but in general I recommend the full L-bracket approach.
Really Right Stuff offers a very wide range of L brackets for just about all brands and models (I use their plates on all my cameras, as well as my favorite tripod, the TVC-24L). The RRS camera plate designs are almost always optimized/customized for each camera for a perfect fit, sturdy and robust yet with minimized weight.