The point isn't which Lisp. It teaches all the concepts common to both Lisps; of the ones from CL, it only misses the idea of a generic function model of OO, an

The point isn't which Lisp. It teaches all the concepts common to both Lisps; of the ones from CL, it only misses the idea of a generic function model of OO, and macros. And honestly, once you've had your mind expanded enough by SICP, learning the rest of CL is a snap. (I know; it took me only a couple weeks to become proficient at CL after taking Berkeley's SICP-based course. I wasn't blindingly amazing at macros, but there's On Lisp for that.)