I'm sure Node is generally faster and consumes fewer server resources than Rails. How about speed of developing things though, that do involve a relational database on the server? Rails has so much in terms of convenience functions that it's hard to jump to anything else, outside of applications where it's clearly not suited. Erlang has been faster and better at async than even Node since before Node even existed, but it's painful to use after getting used to Rails because it feels like a lot more typing and a lot more doing stuff by hand that Rails handles easily.