So far adjusting mains in small increments has amazed me as to the very noticeable increases in performance (120>125>130) while not having much affect at all on fuel economy.
Bumping the pilots from 40>42 did make a difference in fuel economy (about 10 miles/tank to reserve), but not so much in performance. More importantly, to me anyway, was the difference it made in the tone of the pipes. It lowered the tone, and kind of "beefed it up" in a good way - well worth the change.
