I have had a look at the away3d render code and read a few articles about the drawTriangles(). It seems that this method is not necessarily the fastest solution, due to a missing z-buffer implementation. Papervision is in Flash 9 sometimes even faster than in Flash 10!
Well, what does this mean? I think the core issue is that the Flash Drawing API is unfortunately not fast enough to handle more than 20′000 triangles. I have decided to try-out Alchemy… I will first have to setup my windows machine, since my Mac is still running on Tiger.