Crate,

I like the idea of making them better, but I wonder if everyone agees on what "better" is. Many full-scale designers are focused on improving efficiency: lift versus drag, or specific fuel consumption. I don't think that these models are really in need of improved efficiency from that sense. A better airfoil for this aircraft type, in my view, would be one that produces the required lift inverted with the minimum of change in elevator deflection. And while doing that it produces the smallest amount of change in pitching moment (or required elevator deflection to maintain trim) with airspeed changes.

Sure, low drag is important for vertical performance, but I think we've got that one figured out. It seems to me that the "flys like it's on rails" and maybe the "lowest weight for a given size/shape" properties are the things to optimize.

Mitch