Prope is well known in racing and speed flying ,until a few years ago it was a big part of the pulse jet fuel , but they had trouble getting it in Calif . speed now has a 10/20/70 % nitro, caster, methanal rule.  in racing the 1/2 A class still has an open fuel rule most run around 50 % nitro ,and they seem to run better replacing the methanal with prope .  more responsive and easier to set the needle.
  the big problem with prope is that once opened it evaporates very fast . unless totally resealing the container, usually just enough is mixed to get through the contest    ,i dont think there is any advantage  to using prope for stunt

a little diff  deal,,the jet guys are now using  nitro/ methanal combo, Joey can give the %'s i think it starts and runs better than the prope, but needs a larger tank

 
  only from a distance.. his Bi-Slob is crazy