We clearly are not going to agree on this, so further debate probably won't help.
So we have three views,
Vmp
Between Vmp and Vmd
Vmd
Here's another question taken directly from the JAR CQB (which will not resolve the debate)
Maximum endurance for a piston aeroplane is achieved at?
a. The speed for maximum CL.
b. The speed for minimum drag.
c. The speed that corresponds to the speed for maximum angle of climb.
d. The speed that approximatley corresponds to the speed for maximum rate of climb.
The examiner's answer is option d.