Basically here's the problem with the Phantom: It's a big flying pillow.
This is approximate in flight attitude, minus batteries. Mavic tucks batteries neatly underneath and the fuselage streamlines decently.
This sums up why the Mavic will fly 121,400 total ft, climbing over 1100" and do it with 109Wh of motor power.
I'd still like to see one of those secret phantom .dat files to convince me why the Phantom has efficiency potential.
Lolo has his setup so that it flies with near zero lean. You see how his horizon is at the zero point? He minimizes the frontal area and uses front props as a wing which are basically flat. The rear props are doing nearly all the forward thrust and have high pitch 4.5 props. Pretty sweet stuff! With 4s he can shoot for 200K total distance at relatively high speed.
For comparison, my mavic needs 170ish watts on average for flights at that speed. His needs only 109W. Big difference!