I use Spacemacs for Clojure at the moment and I quite enjoy it. My only problem is there doesn't seem to be a way to insert a newline in the repl without submitting the line for evaluation (I want to be able to structure a function definition for readability, for example, rather than having to have a single huge line).

I did also have to stop smart-parens from auto-closing backticks, but that was a simple fix.