Luminus has been around a long time and Kit is newer. Most Clojurists believe in libraries over frameworks though so that's why you don't hear about web frameworks much. I've messed with Luminus a few times and it is really easy to pull out parts and swap in almost any bit of it. They document a lot well and make it really easy to pick different parts out of the gate like different DBs, JavaScript libs, and a lot more. The maintainer roams HN frequently as well :)