You might also want to take a look at Negroni since it's supposed to be more idiomatic. There's a blog post about this by the author himself.
http://codegangsta.io/blog/2014/05/19/my-thoughts-on-martini...
http://codegangsta.io/blog/2014/05/19/my-thoughts-on-martini...
Negroni and Mux are great to use, and typically I will go back and refactor the code to squeeze out any extra performance if it's needed and the project has proven its worth, but Martini has middleware that is hard to beat and easy to set up to get proof of concepts out the door.