Why I don't use Groovy: I just cannot.
Groovy is a cool language and I'd like to use it. But how to?
Whenever I start editing a Groovy script with my favorite IDE, I notice that I really don't know all the Java APIs by heart. Hands up who can setup BufferedReader/Reader/InputStream/whatever chain without code completion and parameter help in the IDE? Ok, Coyote offers some basic support like syntax coloring, but this doesn't help very much.
What I always need to do is to open a dummy Java class in parallel and edit all my Java-related expressions there using the full-blown IDE support. When the statement is fine, copy&paste to the Groovy script. But the easy-of-use promised by a sweet syntax is complete compromised by that.
I'd love to do sketches or API experiments using a scripting language, but for the lack of IDE support this is much easier using Java itself. That's a pitty.
From what I here from Eclipse people, the situation over there is pretty much the same.
So what do you do?