Mounting to Camera
Mounting options are good, but have a few flaws. The rail mount is light, small, sturdy, and easy to tighten onto the rods. The L bracket works well. It has a handy thumb screw that allows you to attach it to your camera without a screwdriver. The receptacle for the light stand is also a useful place to grip it when handheld.
There are two issues I had with the L bracket though. The first is that I use a cage on my camera which I don't like removing. The cage has many 1/4" threads but none that are centred under the lens which means I need to take the cage off to use the bracket.
The second issue is height (the rail mount also has this problem). To get around the cage removing the cage, I tried to mount the L bracket to a quick release plate that fits nicely onto the cage. When I did this, the hole in the center of the ring light was too low to fit the lens through it. The height is adjustable, but not enough for this kind of use. The same problem came up when I tried using it on a Canon 1DC which has a larger (taller) body. There are quite a few 1/4" threads on the light so a DIY solution to this would be pretty easy to find, but it would have been nice of F&V to maybe include a height extender, or at least sell it as an additional option.