Where Racket has a clear edge on Clojure is learning about it. http://racket-lang.org/ is very good, and the included IDE means you can hit the ground running and start typing code from a tutorial within minutes.
Clojure by comparison is like moving to a new city and trying to make friends (with emacs).
Racket is good that way, but you can get immediate gratification from things like Try Clojure too.
And of course, the Clojure setup is actually attractive if you're already using Emacs, especially since it offers integration with SLIME. No one has been able to do that with Arc yet, as far as I know. (With Racket, I'm not sure.)
Clojure by comparison is like moving to a new city and trying to make friends (with emacs).