Floatingbridge, what you mean is that most of my goals are explained in brett willmot's book? That's because I'm studying from that one heheh. I haven't come to the chapter when they talk about substitutions etc. but it's nice to know that there's more to study there ^_^
By diatonic substitution I mean subbing chords of the same function (in C, subbing Em or Am for C, and that might include sevenths).
It think piano players tend to sound more advanced harmonically because they tend to integrate the melody inside the chord, and that's more difficult to us poor guitar players. But hey, they can't bend a note, can't they? lol