My car was not equipped with ADS but I have activated it, steering gets heavier in Dynamic mode and there is a small increase in throttle response (emphasis on small). I have a manual gearbox so I can't comment on transmission changes.

Did you follow the steps that you have to do via the "Green menu" in car? I activated mine via carista, but there was a second step where I had to go into the MMI's green menu to finish the process. Prior to this it gave me additional drive select options like "Offroad" and "Efficiency" once I completed that extra step those disappeared and I was left with the typical "Comfort, Auto, Dynamic, Individual" options. It was only after that ADS actually began functioning