When speed matters, what you need is a good hacker to make a smart-ass elegant program that goes around the bottle-necks. But I'll attempt not to avoid your que

When speed matters, what you need is a good hacker to make a smart-ass elegant program that goes around the bottle-necks. But I'll attempt not to avoid your question altogether: from my own personal testing, SBCL is fastest. My bias is my own benchmarks. Find your own set.