you should calculate the time within clojure and node and output it. This will take away the startup time. You should also warm up the jvm.
I may play with the type hints tonight if I get time. It shouldn't make it slower.
Uh, if it's slower you should probably look into that.
Startup time for the jvm seemed fair, because node has to start up as well. This should count into the overall time imho.