Early dsg cars suffered less Mechatronics issues, going by number of people complaining on later cars with failures.
Im sure i remember somewhere they did some major changes to it.
Pretty much the same, consol colour and steering wheel was black on the earlier models, and greyer on the later.
Rns510 (touch screen sat nav) came out from 08 as a factory option rather then the MFD2 dvd rom sat navon the pre 08 cars.
All else off the top of my head was pretty much the same.