[shiro]

Yes. Profiler is the secret weapon.

When I write optimized Lisp code, I heavily rely on the profiler of Allegro Common Lisp. Sometimes per-line or per-function isn't not fine enough and I go down to per-machine-instruction level profiling for the innermost loop, which is quite handy.

If you didn't use good profiler in your Lisp environment, well, you can't really compare performance of Lisp and C... (Unfortunately, there seems no such compiler that is clever enough to take quick-prototype Lisp code and emits fully-optimized code.)