Richard, I think there might be some confusion of terms on the technician's part too. In mechanical terms, "compliance" is the opposite of "resistance", so I don't see how an action's being too compliant could result in a complaint of its being too stiff or heavy. The complaint would likely be that it's too loose or too light. A limber (flexible) key is something else. That will make the front of the key more compliant to the pianist's finger, but not the action, and he/she is likely to complain of a loss of power, or of not being able to "connect" with the piano. The pianist's finger will be doing "work", but some of that "work" will just be flexing the key instead of throwing the hammer toward the string. Sincerely, Jim Ellis
This PTG archive page provided courtesy of Moy Piano Service, LLC