In my opinion the game is far to twitchy using the controller on the xbone, it needs a patch of some sort to make it less sensitive. I've fiddled about with the steering settings for hours and nothing gets rid of it completely, especially at low speed. Mode 3 left at the default settings seems to be the most stable, for me at least. You can further improve it by tuning the car and also slowing the steering rack but it's still too twitchy.
The game is also full of bugs at the moment, far too many to mention here but the ones i seem to get the most are engine sounds distorting for a few seconds on almost every lap, lots and lots of screen tearing, car wont turn in any direction other than to the right on full lock forcing you to restart the session, random ghosting through cars in the pit lane. Not sure this qualifies as a bug or if the game was designed this way but when you go into the options menu it takes ages to save (even if you don't actually change anything) and go back to the previous menu
The game is good and the plethora of options available is impressive but i have to say i'm also a little disappointed as well, only because of all the arsing about i've had to do to get the controller set up somewhere near to where i'd expect it to be out of the box.