That was quite elaborative Duke, thanks. So in fact sensitivity is closely related to efficiency and in fact they are expressions of the same thing but differs from one to the other in approach? Mlsst: instead of picking on me and telling me that I have an impedance obsession disorder (in fact I'm a bit neurotic, but that's another story :) ) it is better to explain things the way Duke did. I do appreciate your precious input though because I know you are a very knowledgeable person.
Chris
Chris