Earlier quoted context omitted.
SML’s compilers and implementations are state of the art. Advanced optimizing compilers and multicore are already huge differentiators. Also, Standard ML is, well, standardized. The standard isn’t perfect but it at least allows for a strong ecosystem of independent implementations.
I was under the impression that ocaml’s optimization was pretty good. Granted multicore is not here yet.
MLton is a whole program optimizer (rather than function at a time like Ocaml) and wrings out a ton of performance though compile times are quite a bit longer.