Ok, sorry in advance for the long windedness of this post.  

I have seen that competitive shooting tends to be won by ILF recurves. Modern materials like aluminum, carbon, and foam.  Personally I shoot better with my HH big 5. Fiberglass, bamboo, ebony.

My question(s) is this:

1. Is it the modern materials and consistency within them that promotes the improved accuracy, or is it the "superior" design that these bows have because of the extensive RnD.

2.If I made a hill style d shaped longbow out of these materials what would happen?

I think it is both, materials and state of the art desgin. I have an ILF, TT Titan, black Max carbon limbs, feels several puounds lighter, dead quiet and dead in the hand, smooth as silk.

Good question, I shoot both Hills and ILF bows. I will have to say that I am more consistent with the ILF setups but not by a whole lot. The advantage to me with ILF is the added ability to tune the bow. You can adjust tiller, some weight change, change the grip, add a plunger, change plunger settings, use an elevated rest. Change the limbs, go from recurve to long bow. You can go nuts. But on some days I love playing around, but when I pick up a Hill, just feels so good and simple.

I appreciate the responses guys.