But I think Jason is correct (but I am not certain).

Remember when we were flying ducted fans? The exhaust speed was far slower than our modern day turbines. That exhaust speed is a limiting factor for speed. Even if you had been pushing 13 lbs of thrust with a two pound airframe, you cannot exceed the max exhaust velocity. When your 2 lb DF gets near its max exhaust speed, the thrust drops to zero. So it is limited.

With turbines, some of the same thing is going on. We all know that the Wren Super Sport puts out its thrust at a very high (well, high for model turbines) exhaust velocity. Let's say it is putting out 18 lbs and we have a P-80 putting out 18 lbs too, but at a lower exhaust velocity. When the planes are going 250 mph, the SS will still have say 16 lbs coming out the back where the P-80 may only have 14 lbs. So I believe that Jason's Kramer example is very possible. It is almost as if the SS is in a higher gear and the P-80 has better low end torque (crappy analogy).