Mister T,
you do not really think that the numbers published are the best numbers achieved do you ? The numbers are crushed through a model very close to the RMS ( root mean Square), and ending up in selecting the best achievable performance, should one fly the plane like the manufacturer said it should be flown. Are you still with me ?
If now you are factoring 1.67 or 1.92 for landing and being very happy with the result, the initial number is coming from the very same test campaign, where Vapp is Vapp, Vref is something ( now 1,23 Vso), and the touchdown speed somewhere below that, but close to this specific Vso; how can you be happy with the result ? since the computation at the very first beginning implies that you are flying the plane as it should. I understand the logic behind it, a kind of firewall from fatigue stress, pilot experience , etc.. But you seem VERY happy with the take off part of the scheme, which gives you very little things in order to balance the pilot technique should an engine fail, same test pilots though, no ?
What are your thoughts ?