I'm not sure if I read it in Soartech 8 or elsewhere but Michel Selig commented on trailing edges and model performance at some point and the end result was if you want to go fast or have lower drag in sailplanes then keep it thin, keep it sharp and keep it stiff.

Obviously the same things would apply wherever speed or efficiency is the goal. The complete antithesis to fun fly's, trainers or Stik's of any sort.....