The oil change kits are expensive (about $25).
After the change, oil seeps out of the seals for several weeks, making the rear wheel messy.
The most common installation is to connect the rear cable guide to the post for the rear brake arm. That created an issue with water getting into the joint. After a year or so, it would get rusty and the one side of my rear brakes would not release correctly. I re-routed the cables to attach the rear cable guide to the chain stay. This requires a straight cable guide (Rohloff part number 8260). The only US source I could find for it was Cycle Monkey. At $25, I thought it was rather expensive.