As PJ mentioned in other topic, we have a bunch of old guys who don't seem to die, yet they still get better by age. Examples of such guys are ZSF, ZBT, HYS, YD etc. It seems that as they get older, they refine their internal and external martial arts into fullest extent and demonstrate the true mastery of their specific arts. But several times JY has mentioned that when one is really old its hard to him/her to keep fighting for long time, since his/her stamina has deteriorated by age.
So which is better self of the two, one with great refined martial arts and less stamina or one with less refined martial arts and abundant stamina?
What age should be better for one to claim that he/she is in his prime?