I don't use lisp languages, but one basic difference this has from other lisps is that functions accept multiple expressions, e.g.:

    (defn greet [firstname lastname]
      (def fullname (string firstname " " lastname))
      (string "Hello, " fullname))

In other lisps, you'd have the last expression nested inside a `let` block:

    (defn greet [firstname lastname]
      (let [fullname (string firstname " " lastname)]
        (string "Hello, " fullname)))

which makes the code hard to read and edit IMO. Languages like Haskell and OCaml suffer from a similar problem too.