The Cougar section gives an easier prophang and less hassle over the whole speed range.
the Magic setion is better for super slow agility and floating which is the Cougars only downside, but this gives a little trouble when flying at full throttle as it'll want to climb.

i'm on the hunt for a LA 40 as it'll make my Pheonix even lighter ( read better ) when when i rebuild it, i don't need the power and speed of a 36