Isn't the S3 basically the same car?
Things like suspension settings (some have mag-ride) and other details may be different but underneath the skin they are fundamentally the same.
I was looking at S3's myself as a more sensible alternative to my M140i.
Never driven an S3 but from what understand it is basically the same car, but apparently the drive set up is not as keen as the R and so its a little less engaging, though you do imagine that its only for those who drive more spirited than most who would notice.
Have had Audi though, and interior is a little bit above the Golf in material, but I actually prefer the layout of the MK 7, not big fan of the pop up screen on Audi, but thats a subjective opinion only others may really like it.