I don't know how different the transmissions are in the S4 compared to the A4 and TT, but I've driven a DSG TT many times, and I like it, it shifts very quickly. My A4 is a 6 speed manual and I like how it shifts too. Much nicer than my B5 S4. If I had to choose between the 2, I'd take the manual, but that doesn't mean that I'd be unhappy with the DSG.