it would be useful to have on a "LangX vs LangY" page somewhere at the top of the content a simple list with 2 sides "LangX | LangY" and under each lang title benchmarks it is faster in are listed with maybe the time next to them and maybe in parentheses after it percentage by which it out performs the other language like "http-server 11ms (30% faster)".

edit-0:
maybe also on the language page it could be useful to have like a small list 3-5 items of benchmarks where the language is performing the best but I see this as less useful then the initial idea for comparison page

hope this is useful!