meh, saw the S7 at the autoshow this week. The S6 and S7 is way too expensive for what you get for the money. The A6 and A7 cars are too similar, with the S7 actually smaller for passengers. So we're paying up for less room for the same performance of a S6 (or RS6, whatever the comparison is)? No thanks.
Given this RS7 will come out at around $100k, it is just not worth it to me. RS7 adds some HP and other "fancy-boy" trinkets of high performance.