I also write Haskell in production. Haskell's strongest strength, in my experience, is the confidence I have when refactoring. I've never experienced that kind of confidence making large changes to working code in any other language, even with fairly exhaustive test suites; and without the overhead of maintaining a fairly exhaustive test suite.
In light of that, I would definitely recommend Haskell over other languages for any use cases where you expect you're going to be wrong, repeatedly, about how best to structure your program. Especially in domains that aren't known very well or when the demands on the program are likely to be highly dynamic.
Though really, at this point I would tend toward using Haskell when there is not much reason to pick something else.
In light of that, I would definitely recommend Haskell over other languages for any use cases where you expect you're going to be wrong, repeatedly, about how best to structure your program. Especially in domains that aren't known very well or when the demands on the program are likely to be highly dynamic.
Though really, at this point I would tend toward using Haskell when there is not much reason to pick something else.