I've been playing around with OCaml a fair bit in my spare time too. I've been using Go at work full time for about 4 years so that's my main comparison.

I love OCaml as a language but the ecosystem is really pretty bad. There is just too much fragmentation and lack of libraries. I would have expected more from a language that is over 20 years old.

Don't get me wrong, I want it to succeed since I agree it has a really nice mix of features.. I just have my doubts given its track record so far.