I love Haskell for its type system, but I gotta say that I feel I accomplish about 10x as much with Clojure than I do with it. Being able to quickly beam over my code from Vim to the REPL, and seeing my changes happen in real-time is so incredibly valuable, and I personally feel that Clojure's concurrency is a lot easier to grok than Haskell's.

I also feel that Clojure's tooling is a lot nicer than most languages, and especially Haskell; Leiningen is very easy to use and Fireplace is a really simple and nice plugin for Vim.