This is my second audi,I upgraded my 2008 A6 to a 2010 A8. I also considered the BMW 550i GT and 7 series. I chose the Audi because it offered the best combo of luxury, performance and value. If you look at raw numbers of horse power and 0 to 60 times then the BMW shines, but if you drive the two cars there is no comparison. The Audi's acceleration is like butter, the car seems to move effortlessly. I was always skeptical about whether or not the price jump from the A6 to the A8 was really worth it, but after driving both there is a big difference and I believe the cost is worth it. To be clear I am a fan of the A6, but I felt it was just a bit under powered with the 3.2 FSI engine.