There's nothing to filter your movements like you might find on Forza, but you can find some suggestions on how to make it more manageable. There are a number of above average drivers using gamepads, it all comes down to if you have the fine manual dexterity and are willing to put in the practice to master it.
I am using a controller at the moment since having to get rid of my Fanatec, it is actually one of the better sims using the controller imo.
Whilst other sims filter your inputs, it can make it difficult on tighter turns such as in AC.
However, it does make it twitch with iRacing, the solution (after too long playing Forza 4 in leagues with a controller). Keep the left stick pushed up against the stop, then roll the stick left and right, while keeping it pushed up, this will give you something to push against, and allow you to do smooth and small motions without it being twitchy