@212 man,
it is given in several articles fairly clearly that till the knee, the hepter is considered to be in a full power climb while above the knee it is in level flight. of this i have definitely have no doubt. your post yesterday quoting paco also refers to the same.
a further study on the topic also brings out that reason seems to be due to management of rotor inertia.. something similar to what mathew has said in his post