Good question....and you are right. The GTR dominates the RS4 in terms of pure performance and technology but the RS4 has some special qualities that make me want to keep it around.
To be honest, the longer I have had the RS4, the more I have come to respect it. I love its overall balance, its exceptional aesthetic qualities and the fact it can be driven on any occasion. I really believe that the RS4 may be one of Audi's greatest accomplishments.