Originally Posted by JohnVidale
It seems a little ironic, if I'm reading you right, that my milquetoasty driving has less use for the xDrive, while, if there's a benefit from your having the 1000 hp of an M Sport 335i, it may well be when the "tires are turning to smoke", and the xDrive could be useful.
The difference is turning the tires to smoke is not only surprisingly difficult on these cars, but very easy to modulate, even with traction control switched off. You know when you've lost traction and it's very easy to push the car and keep on the power. The 3 is not tremendously powerful in either stock form and on 255 series summer tires have a large amount of grip...my Corvette by comparison was 500 lbs lighter, had 525hp and would quickly destroy the standard 275 rubber.
AWD is simply more predictable...oversteer terrifies some people. Otherwise it's the most fun you can have with 4 wheels.