works as advertised. If you are using it on the rm3di series, to me it's just as simple to rotate the back on the mounting plate. Arca has IMO the best design on the mounting, as you can you release it with one hand and rotate the back with the other. As a shooter who does this a lot, I found the Arca the best and quickest way to do it and securely.
All of the R mount lenses come with a ring that you remove if you use the Rotamount, thus you don't have to change anything, all the focus cards stay the same.
Paul C