Cabo is basically a tourist/party town. San Jose del Cabo is much nicer (but getting more "touristy" all the time). Todos Santos (about an hour north of Cabo) is still pretty laid back; and some of the beaches between Cabo and Todos Santos are absolutely spectacular.
Thanks for the feedback. We've avoided going there in the past because our heads were filled with visions of drunken college kids and crowds of tourists but my aversion to these things evaporate when someone offers me a free timeshare to stay in.