I understand your suspicions: switching perspective is something techies have a difficult time with. Is Arc a language or is it a bunch of macros on top of MzS

I understand your suspicions: switching perspective is something techies have a difficult time with. Is Arc a language or is it a bunch of macros on top of MzScheme? It depends on how you see it. Clojure is 100% compatible with Java, both ways in a straightforward manner, so you can easily argue that it's still Java. That's been the smartest design decision ever by its designer. You have to understand whether your clients are interested either in leveraging the Java technology or employing code-drones. In the former case, Clojure will be fine; in the latter one it will not. Popular wisdom teaches that most people remember the result, not the way you got it. If you use Clojure and succeed, you'll have your own way.