Not an expert, but I was paid to write OCaml and Haskell for several years. There are pros and cons but my conclusion is that Haskell has cool features but is too complex. I can iterate faster in OCaml, with the same safety benefits. Learning curve is also less steep for beginners. I think it's also more suitable for programming in the large thanks to the module system.
I'm pretty sad that OCaml isn't more popular than it is.
I'm pretty sad that OCaml isn't more popular than it is.