OK, I was definitely neglecting drag, I was thinking in terms of low speed maneuvers. Like a punch out from a harrier. But true, this is an IMAC discussion. However, drag just helps make my point, and the gains would be higher than 25%, not lower.

My example, 26 lb airplane, with 30 lbs of thrust, and you are climbing at whatever airspeed causes 3 lbs of drag. You have one pound of excess thrust. Take a pound of weight from the plane, and in the same situation, you have 2 lbs of excess thrust. A gain of 100%. My point being, in a vertical that's what you percieve, not the 4% weight difference.