What are the key differences between Audi's quattro and Porsche's all-wheel drive systems?

I am interested in purchasing a high-performance sedan, specifically looking at the Audi A4 and Porsche Panamera. Both offer all-wheel drive capabilities, but I'm wondering how they differ in terms of performance and functionality.

The main difference between Audi's quattro and Porsche's all-wheel drive systems is the placement of the differential. In the Audi, the differential is located between the engine and transmission, while in the Porsche, it is located between the front and rear axles. This results in slightly different weight distribution and handling characteristics.

While both Audi's quattro and Porsche's all-wheel drive systems provide excellent traction and stability, the quattro system has the additional benefit of being able to actively distribute power between the front and rear wheels for optimal performance in various road conditions. Porsche's all-wheel drive system, on the other hand, is more focused on providing maximum traction and handling in high-performance situations.