My handbook says on p156
"If necessary, a spinning driving wheel is braked. This improves the vehicle's directional control and driving power, particularly on snow and ice as well as on wet or slippery roads."
Which sounds great in theory, but in practice results in a whole load of wheelspin on the low-grip side followed by the ECU stamping on the back brakes and any progress you were making being suddenly completely halted

There's one particular junction I use out of a single-track side road that has such an inclination that the inside rear wheel is always completely unloaded - with TC turned off I can make decent progress out of the side road without worrying, with TC turned on my choices are either to pootle out at walking pace and then try and scamper away from the oncoming traffic (it's a fairly busy main road) or get half way out and have the ECU decide enough is enough and turn me into a rather nice stationary road block..

The M3 with it's LSD has no such problems (although the lane is very much not suited to the M3 - much harder to plough onto the mud at the side to avoid the oncoming crazies!)
