[gtrak]

Yes, having to understand the details and implications of clojure's compilation was definitely painful, but the implementing code is accessible. There's always going to be some performance bottlenecks, I guess I'm more concerned with how hard are they to identify and overcome than they might have been having coded stuff up in pure java from the start? Or, once you're committed to a design, say refs and STM, and you hit such a problem, is it difficult to change course?