Not sure on relative popularity. If you haven't already, you should try it! Here's why I like it:
- Very consistent, easy to keep the whole language in your head
- Stable, core rarely changes ("accretive only" mindset).
- REPL
- Focus on a handful of data structures which will solve 95% of the problems you face, rather than a deluge of complicated abstractions.
- Excellent concurrency primitives
- Access to Java libraries if a Clojure equivalent doesn't exist
- Macros
The only blemish for me was horrifically bad error messages.. other than that it's near perfect.
