lol mine are RS4s and i agree Id happily have either set, but these are the ones i knew more about and a style that i though (at the time) would suit my car more but I was very wrong, I think both suit the car very well RS4 and 6's.
now the next deciding factor may be that: RS4s are everywhere, on lots of golfs boras etc, so wont be that fresh, however lots of people on this forum have rs6s on their leons ... up to you
as neither will be a bad choice