A mate did a demo for me of the TSM system on his E-Revo just the other day .
He had it set so he could adjust it on the Multi Function Knob on the Traxxas transmitter .
On a wet road , running 6S , with TSM set to 0 the car was very hard to control taking off . You had to get on and off the throttle and counter steer , looked only semi controlled , you knew any second it could spin . At about 40-50% , the car still snaked its way up the road , but with a bit steering input , looked much more in control . At about 70% , he just mashed the throttle and only made a few small steering inputs , the car ran pretty much straight ( maybe swayed a foot or 2 , remember , on a wet road ) .
I was impressed !!!
Getting a car from stopped to full speed in a straight line , I would say it works .
As for other situations I can't say , my mate wont let me borrow the Revo ...lol