What are the key differences between the Audi A6 and A8 models?

I am considering purchasing an Audi and I am trying to decide between the A6 and A8 models. What are the specific differences between the two in terms of design, performance, and features?

The Audi A6 is a mid-size luxury sedan while the A8 is a full-size luxury sedan. The A6 has a more sporty and agile design, while the A8 has a more elegant and refined look.

In terms of performance, the A6 has a standard 45 TFSI engine with 248 horsepower, while the A8 has a more powerful 55 TFSI engine with 335 horsepower. The A6 also offers a sport-tuned S line package for even better performance.

Both the A6 and A8 offer a wide range of high-end features such as Audi's virtual cockpit, MMI touch response system, and driver assistance technologies. However, the A8 comes standard with more features, including a heads-up display and top-view camera system.