If I'm not mistaken chunking is only supported on some of Clojure's data structures. Reduce is certainly the better option with vectors (and maps?) if you write

If I'm not mistaken chunking is only supported on some of Clojure's data structures. Reduce is certainly the better option with vectors (and maps?) if you write your own loop/recur you'll simply be duplicating the existing implementation. Also I really can't imagine using loop/recur on anything except for vectors and maps most of the time anyway, so why not just use reduce?