Even with a tiny class with a single route just entering text causes pauses of up to 30 seconds. Even editing comment in a class that implements a spray route hangs.
(And I'm not even going to harp on that a typical spray file is fully underlined in red.)
I know this has been suggested before, but a great to work out issues the plugin would be to work with spray or scalaz or shapeless for a few weeks. (Of course it may take a few months to fix all the issues).