Oddly enough it was the opposite for me. I think I might have given up on Haskell if I hadn't learned O'Caml first. It's been 15 or so years, so I'm sort of guessing at this point, but I think the combined cognitive effort of going from typical imperative languages to Haskell and the whole algebraic data types+pattern matching thing might have broken me.

I found Haskell much more practical because it makes refactoring truly easy, but I'm very "programmer-centric". I mean 'refactoring' in the strict sense of preserving absolutely all the existing behavior, including side effects. That is extremely difficult if you can have side effects all over the place. (Strictness obviously helps a lot, but it also has downsides.)

Btw, given your experience and if you want to try Lisp seriously I'd probably recommend Racket, Typed Racket and their Turnstile experiment(?).