To be more specific, the S5 Auto box is a tiptronic automatic transmission, or basically a torque converter.

The A5 comes out with 2 different types of auto boxes, depending if you have the normal, front wheel drive, or quattro. The normal, front wheel drive comes with Multitronic, which is crap and you want to avoid this type of auto transmission at all costs. It's basically a CVT type of transmission where the gearing constantly changes and IMO does not work, unless you 100 years old and drive like Miss Daisy. The Quattro on the other hand would be the A5 to go for as this has the Audi S-Tronic transmission, or what was mentioned, "DSG". This is the dual clutch transmission and works like a charm.

I only wish that Audi had bought out the older V8 S5 with S-Tronic, but apparently it could not handle the torque of the engine at the time. Obviously the newer S5, RS5 and even the R8 now has S-Tronic.

Funny enough, the RS7 still uses a similar Tiptronic transmission as the older V8 S5, due to torque issues with the engine. It produces so much torque, the S-Tronic from the normal S7 will break.