I have used python javascript and clojure and let me tell you that repl driven development is not exactly what you get with python and javascript. The most frustraiting thing after having used a lisp is the fact that you can not connect to your program while it's executing. In node for example i wish i could just connect to the running server and test some functions with the current program state, like database conections etc. In clojure you can do that from your editor and that is awesome it's really powerfull. You can just point to a function and execute it inside the running whole.