passed commercial written

so i just passed the commercial written, and i hear that the CFI
written is half of the commercial written information, with the other
half being new material. Any reality to that?

I also have watched a few videos of fellow group members flying, and
wondering how many of you are running lean of peak? My airplane is
burning less than 7 gph, when it burned 9 or more if i just left the
mixture in. great way of flying, and i have an annual coming up that
should show my cylinder compressions improve.