Currently driving RS6 (560hp version), feel the car is very stealth and extremely powerful, and extremely stable when its wet.  The downfall of RS6 is its heavy front makes the car feel heavy, but still does well on twisties, but the interior feels extremely outdated when it compared with the new Panamera.  The interior of Panamera is just soo fresh and high tech. looking....  seriously considering replace my RS6 for the panamera, but its a lot more expensive and heavier than RS6.... I had promised myself not to get another heavy car anymore.... regardless of how much power, the weight is always the issue.....