2011 Mercedes-Benz CL63/CL65 AMG: V8 Or V12?

For your premium luxury grand touring needs, the newly minted Mercedes-Benz CL63 AMG offers a 5.5-liter twin-turbo V8 with 536 hp. Need something faster? The CL65 AMG has a 5.9-liter twin-turbo V12 and 621 hp. Decisions, decisions.