I'm not sold on the Boss intake as you won't see much improvement unless you have the supporting mods for it. The boss intake does pick up power after 7000 RPMS but how often are you going to be there while racing?
As far as the intake and tune combo; you can't go wrong with that setup. The car feels much quicker and the dyno numbers have shown it.
Looking at dyno sheets of before and after for the boss intake manifold I wouldn't expect much of a drop in e/t.
Peak numbers don't mean anything, all that matters is area under the curve and the boss manifold loses power in the mid range and then gains right near red line. I'd expect the area under the curve to be only slightly changed.
There is a reason that Ford didn't just put a different manifold on the Boss and call it a day.