As I have said before, I have never really written anythign over say 20k or so in C, probably not even over 2K to be closer to the truth, and when I have written code as closely as I can in both C and S, the S has always been far faster, and far more compact than the C code, but as you point out, this will not be the case in large programs.
I will go with that, as I simply cannot argue with somethign I dont truthfully know about.