I use Nailgun[1] with vimclojure[2] and lein-tarsier[3] to avoid the JVM startup pain. You'll end up with a JVM instance (server) running all time and the possibility to evaluate code from many different clients like REPLs and the editor itself.

Changes to the code just need to be evaluated again to override the previous function definitions. It ends up being a really fast workflow.

1: http://www.martiansoftware.com/nailgun/ 2: http://www.vim.org/scripts/script.php?script_id=2501 3: https://github.com/sattvik/lein-tarsier