Light Table isn't a Java IDE, so this isn't a fair comparison. For a dynamic language, where a REPL will no doubt be part of your workflow, an IDE that aims to

Light Table isn't a Java IDE, so this isn't a fair comparison. For a dynamic language, where a REPL will no doubt be part of your workflow, an IDE that aims to merge the process of editing and interacting is probably quite valuable. Like emacs with slime but less daunting to the unfamiliar.