Litebulbs, we know the plane traded a lot of velocity for altitude. I worked out the simple math on that one going back to mgh and 1/2 mv^2 basics. It lost around 40% to 50% (I'm not sure of the knots to KCAS conversion here) if we presume 100% efficient conversion. Another 10% for aerodynamics would not surprise me.
(It takes a LOT of pushing these days but when pushed that hard I do have a nasty habit of "doing the math." It happens in political discussions, too.)