Hey dude, I have KWV1's on my RS6, had them for two years, simply awesome and soooooo much better than DRC! The V3's are mainly for track use, according to KW. I'm not spending any time on the track, so I went for the V1's and I don't regret it.
2004 Audi RS6 - 4.2 V8
1993 Audi S4 - 4.2 V8
2007 Audi A8 - 4.2 V8