The new kid on the block, IntelliJ IDEA, has had a meteoric rise. A free community edition has been released, which works well with LeJOS projects. The only configuration that is required is that you open the Project Settings/Configuration window and add the root folder of the project, that is, the ev3classes and DBusJava folders, to the source/content roots of the project.

It does not have the ability to compile or deploy the code, but the advantages that an IDE brings, as outlined earlier, are all available.