Yes, there is no way to permanently disable it and even pressing the button to turn it off still leaves a secondary layer of traction control. It would not be a big deal if it just was not so intrusive. How intrusive? The car automatically applies the brakes, will tighten the seatbelt, and also cut power. This makes getting a fast laptime out of what's supposed to be an AMG vehicle very difficult.
Porsche on the other hand with the Cayenne allows one to completely disable traction control. This allows for some ridiculously impressive drifts in the Cayenne Turbo. Yes, you can actually drift a Cayenne. This clearly shows the different philosophies of the companies and Porsche proves even with its SUV it is simply much more enthusiast oriented.
The Cayenne Turbo ends up lapping 1 second faster than the ML63 AMG. It would be interesting to see how much better the ML would be without the ridiculous electronic nannies killing the fun. Seriously AMG, what the hell? You have been doing so well lately.