Depends on how much instability you are willing to tolerate. The TSC system REACTS to sway as soon as it senses it. It takes the computer just a few milliseconds to identify the sway and then to apply corrective braking. The sway control on a WDH tries to PREVENT sway from starting in the first place so the TSC doesn't have to REACT to it. After pulling my TT with my Canyon for 30K miles in 4 yrs. I can feel that "uncomfortable" instability whenever I'm following a semi or in buffeting cross winds and forgot to engage the sway control on my WDH.
The TSC working with the sway control of my WDH saved my a$$ a few times when I had to do a high speed swerve to avoid road debris on wet roads. I strongly recommend you get a good sway control WDH to work with your TSC!
