While the Lisp Machine does use lists, the benefits of CDR coding were / are quite overblown. The Lisp Machine also used other data structures far heavier than lists.

The Lisp Machine macroinstructions aren't that complicated, it is a basically stack based machine -- the most complicated thing was handling of the function arguments from Lisp (FEF); which has complicated semantics when it comes to handling optional, keywords, and what not arguments.