The OS .55 is a great engine and will drop right into a 40 size plane, The mid wing isn't what makes the Edge harder to fly, it's the wing loading, airfoil and everything else that makes the edge so aerobatic, The pulse is also a great plane and one of the guys in my club has the same setup your thinking about with the OS 55AX on the Pulse. It flies great and when he opens the throttle it really moves out, so just remember when over powering, you really need to use throttle control. I have a few members that seem to think that the plane is either full power or deadstick and never anything in batween but the 55 (I have one too on a Revolver) is a real sweet running engine and has a nice midrange and instantly snaps to full throttle when given, A real torquey engine. Your going to like the combo with the Pulse.

Dauntae