The Caml XML parser I wrote was competitive with XML4C (slightly faster),
and blew XML4J out of the water (10x).

This was using the native-code compiler.

The Caml XSL processor I wrote handily beat Java XSL processors.

My guess is that if you're thinking of writing in C, and you don't
need low-level access to real memory and such, you will find that CAML
is more than fast enough.

--chet--