[junkyarddog]

There's more to F# then HM type inference plus ".NET's OOP and subtyping". OOP and subtyping are rarely used. While it lacks some of OCaml's powerful features it shares many core features such as algebraic data types, exhaustive pattern matching, immutability by default, Option types and so on. It's also arguably easier to read with it's white space significance and not needing the rather distracting "in" keyword.

Having the vast .NET library is a big plus for the language, of which OCaml has no equivalent. Other great features of F# are type providers, straightforward multi-core programming and units of measure, which I don't believe have OCaml equivalents.