<i>Ruby-style OOP brings a lot of complexity and baggage which Clojure avoids by not being OOP. For example (ignoring Java for the moment), in Clojure land you don't have to worry about a member being public/private/protected, and there are few times when you have to worry about inheritance and class hierarchies.</i><p>In my limited clojure experience I actually found the lack of a clearly defined object model to be something of a handicap. In a language with a single, solid object model it's easy to build consistent interfaces to libraries because they all follow the same conventions. In languages like scheme or clojure these things become more heterogeneous and less predictable.<p>The forthcoming protocols stuff in 1.2 might nail this down though.
no real negatives there... I'll fix that. Immutable-by-default and lazy-by-default made simple tasks awkward, its macro system is like CL's but gets in your way a little more, and because it's java it takes forever to start.