MT is faster than auto.
A master of controller driving can easily be as fast or faster than a wheel user, because this game has a very helpful invisible hand for controllers.
Theoretically, a controller should be much more difficult with it's tiny levers, and the 'compensation' for that is relatively generous in GTS.
Some driving games are less so, but GT Sport is unabashedly controller friendly.
That is why, in a lobby race, the hunting kind of lines and often erratic steering of a controller driven car can keep pace with a wheel driven car with a smooth clean line. A sort of 'BoP', so to speak, for the input device so that everyone can race together regardless of their equipment.
A wheel will make you a better, and more consistent driver,
and the feel and feedback you get from the car and the road, is several levels of experience beyond what you can get with a pad.