I have found this thread to be quite educational. Thank you all. I think J.T.'s summary brought many of the good points made into a unified, or at least more easily recognizable statement on the importance of understanding takeoff performance data to a somewhat more advanced level than is provided by typical type training. As illustrated by mutt's point about the differences in certification methodology used in the certification of older vs newer aircraft, It seems that it would be useful to learn what assumptions were made in the performance data for each specific type we fly. It's nice to know what margins are and are not built in. Since this is outside the normal curriculum of a standard type training course, I'll consider it to be an advanced learning assignment which may come in handy someday on a limiting runway. Once again, thanks.
Best regards,
Westhawk