[lobster_johnson]

That seems like a false dichotomy to me. Clearly I can worry about the cost of hashes and be using Ruby productively and performantly. (Unless I were writing programs whose performance was really dependent on hash performance; I don't use Ruby in those cases.)

Anyway, everything adds up. Even for webapps in Rails or Sinatra, the sheer number of method calls in a single template may contribute significant overhead to the rendering of a page. Which means that shaving a few microseconds off a method call may in fact boost performance measurably. I am hoping this will be the case with named arguments.