I really like the power and flexibility of Lisps, but I am so much more productive with good(!) statical typesystems.

Looking at both typed racket and now sugar, it doesn't look really good to me. I think I would rather decide to go straight for Haskell/Scala/... or Lisp/Clojure. Maybe it's not really possible to combine both in a good way _yet_, or maybe it's not possible in general. I hope for the former.