When I got my S3 saloon last year, the old S4 was coming to the end of it's run and was about the same price. I chose the S3 mainly because it was much lighter than the S4. I'd be lying if I didn't say lower running costs were also a factor, but that wasn't first and foremost. The S3 is still 200kg lighter than the new S4. I would assume this will be similar for the RS3/4. That's 200kg less to accelerate, 200kg less to slow down and 200kg less to get round corners. For the RS4 to be as quick as the RS3 it will need a bigger engine, which means more weight over the front wheels. I also prefer the look of the S3 over the S4, so when the time comes, I'll be looking at the RS3 Saloon. If the RS4 was the same price, I'd still choose the RS3. Besides, I honestly couldn't care less what anyone else thinks about my car, as long as it's what I want! And I want something small, light and fast! (with 4 doors)