The smaller the disk area the higher loading for a given heli. Blade weight is important as energy is stored in the blades as inertia, If carbons are heavier than woodies they would initally be more responsive. I have a feeling the FRP blades are probably the heavist, but that is just a guess. I think woodies would make an auto nearly impossible, because they are so light. It all comes down to how you want it to fly. The bigger the blades the more stable (lightest disc loading) but a little less response, the smaller the more response due to the motor being able to spin the blades up quicker, and less blade to move around( this assumes same blade material). Think of it is a similar to increasing span on an airplane. In therory the shorter blades would do better in wind. The longer blades also require more power, so flight time would be reduced some. It is all a matter of what you want and experimentation. It would be interesting to fly a Rex on 288s.