So to re-open this topic, has anyone come to a simple yet definitive difference between a SDP and the data that we use via flight manual/laptop computer (C-5/KC-10) or aircraft mission computer (C-17)?

I was under the impression that the C-17 (my aircraft) considered climbout data from the end of the runway and that the Jep SDP considered climbout data beginning from the CFL - but now I've concluded that the C-17 mission computer does consider the amount of runway following rotation (TORA/ERAC) into the obstacle clearance equation...

The SDP obviously allows us to go "lower" than our mission computer does, because in the C-17 when we can't get data against a OEI climb gradient, we are allowed to clear the requirement from our computer as long as we ensure that we meet the Jep SDP's COF (Climb Out Factor - flight path)and CFL.

But wherein is the difference between Jep SDP and Air Force climbouts? It would seem again that with the Jep SDP we are allowed to be "lower" than the AF Terps...anyone?