Making the switch from L-lever to C-lever
Tuners who use L-levers push to flatten strings, and pull to sharpen them. On verticals, tuners who use C-levers do the same; but on grands, they do they opposite: They pull to flatten strings, and push to sharpen them.
Tuners who use L-levers are used to working with their hands widely separated. On verticals, tuners who use C-levers separate their hands in the same way; but on grands, they often find that their hands getting in each other's way.
For both reasons, switching from an L-lever to a C-lever is typically effortless for verticals, but requires some relearning of technique for grands.