Weird, as I was browsing the language shootout, I got the impression that SBCL produces damn fast code, in most cases comparable to the code emited by GCC or Java 6.
http://shootout.alioth.debian.org/debian/benchmark.php?test=...
http://shootout.alioth.debian.org/debian/benchmark.php?test=...
Notice that there are more up-to-date measurements available from the homepage