Today I got a chance to play with an rm3di for a few hours. The big focus ring was very precise, but I also found it stiff. My wimpy fingers were starting to feel sore after just a few spins of it. (I also have issues with my hands that make certain gripping motions more painful than they should be.)
I haven't had a chance to try an Alpa lens yet with their custom focusing helical. Can anyone who's used both comment on whether the ring turns more easily?