DrCondor

Having spent 110,000 miles in my RS4, and a few in and RS5 (which has more tech but only a bit more hp), for my purposes the S6 was the better choice. It's 13" longer with a 10" longer wheelbase, so it does 'drive bigger', but it is effortlessly faster straight ahead than either the RS4 or RS5...much faster. I am currently over 36,000 miles and don't regret my choice a bit. Incidentally, on the rare tankfuls during which I am well behaved it really will get 28 mpg, which is also better than the RS4, not that that is a likely selling point on this forum.

superswiss

^^This. I looked at this question as a current RS5 owner a while back. Would I trade it for an S6 and the answer was no, unless I really needed 4 doors. The S6 was designed to haul your family at triple digit speed on the Autobahn in comfort. The RS5 is a GT providing comfortable long distance driving at speed for 2 + luggage and sport car like handling on the curvy roads and the track. Two cars at the opposite side of the spectrum. For me the S6 is a bit pointless in the US. You can't really have any high-speed fun over here, but you can have mountain and canyon road fun, so therefore I much prefer an agile and great handling car like the RS5. The S6 just can't keep up in the handling department. The RS5 lets you drift it around a corner even on dry roads w/o the ESC stepping in for example. However, the flat handling of the RS5 comes at the price of a firm suspension.

m444

The RS5 is more of a track car. No adjustable damping for street driving on crappy roads. Also, since all the power is mainly up at high RPM, it would only be fun when driving it hard, which is not so good as a daily driver.

I prefer to have low RPM torque and a reasonably compliant (adjustable damping) suspension in a daily driver for the lousy streets of the SF Bay Area, which precludes the choice of the RS5.

The S4 is a nice car, but the S6 has a lot of goodies the S4 does not have, such as HUD, night vision and adjustable air suspension.

EHLO

I was considering an RS 5 with an APR SC to make up for the low end deficit compared to the 4.0 TT, but then APR dropped developing it, so now I'm back on the fence waiting.