I tried it once, though I was fooling around (as in, almost not caring if I was on the road or not). It seemed a little trickier to drive, but then again it was my first time driving on the Ring with the X1.
Side note, I don't think the X1 is unrealistic even on the racing tires anyway (though I wonder what the tires would need to be made of to hold 8 g). All that stuff is banned from racing for a reason.