https://github.com/clojure/core.typed
> multimethods
http://clojure.org/multimethods - also, arguably better for many use cases: http://clojure.org/protocols
> native and efficient executables
Clojure performs much better than popular web development language implementations like Python, Ruby or Node.js. See http://www.techempower.com/benchmarks/ People have found it performant on harder problems: http://clojurefun.wordpress.com/2013/03/07/achieving-awesome... And it's possible to produce executables that depend only on the JVM, which is just as easy as fully-native for deployment.
I grant you the one about the Common Lisp condition system. I wasn't familiar, but reading about it (http://c2.com/cgi/wiki?CommonLispConditionSystem), it does look intriguing. Apparently something inspired by it is available as a Clojure library, but the last commit was 10 months ago, and I hadn't heard of it till now: https://github.com/scgilardi/slingshot
I'm reading their "Why Dylan?" page:
http://opendylan.org/documentation/intro-dylan/why-dylan.htm...
and I don't see anything that makes me want to go run and install it. I'm already used to dynamic, garbage-collected, infix programming languages that can be used in a functional style. Heck, JavaScript is one. Integers and strings are objects, cool, but how does that help me prototype faster or write more maintainable code?