Surely the two technologies perform differnt tasks...which is why they were both fitted to the same cars...

as I understand it the LSD transfers power to a wheel with grip (effectively)..thus allowing you to get more power down...

the traction control using brakes (i.e. braking a spinning wheel) is about removingthe rotational velocity from the wheel such that the maximum grip available to the wheel is utalised.. basic physics comes into play here...a spinning wheel isnt effectively transfering energy ...its making smoke...

I understand that the traction control wasnt fitted to (i think) auto boxed cars..for a fairly obvious reason..the box should just change up unless you are in really bad conditions and driving like a complete loony!

the above may explain why it didnt appear in the US..it certainly did in the UK, but i have only seen it on manuals...and bear in mind auto's are tremendously unpopular over here...