As my dd i'm driving right now '14 Audi S8. I'm so impressed with the car that I ordered '17 S8 already. The car is THE BIGGEST sleeper ever, especially with the APR's tune.
Such a joy to ride, plush yet with instantaneous power delivery. The only car barely close to S8 was MB CL600 which I miss sometimes.
Anyway, you owe it to yourself to at least test drive Audi S8.