I use it, as do many of my students. I also cheerlead for it here and there occasionally because I think that it occupies a unique sweet spot in the Clojure ecosystem, combining substantial, useful functionality (even if one must sometimes augment it with command line calls to lein) with elegance and usability in a way that nothing else in the ecosystem can touch.
The only downside is exactly what you note: Clooj's author, while extremely helpful when he has the time, doesn't often have the time to help or fix things, and nobody else with the requisite skills and time seems to be stepping up to the plate.
From my perspective a better-supported Clooj would be of tremendous value to my work, to my students' work, to anyone teaching or first learning Clojure, to many advanced programmers who don't need the features of more complex IDEs and don't want to deal with their complexity, and to the Clojure community in general.
So here I am cheerleading again. I don't myself have the skills/time to develop/support Clooj, but if anyone else out there does, and wants to contribute to a project that will help a lot of people and make a lot of people happy, then please check it out!
-Lee