I'm not sure I agree with that Ratty, there seems to be a lot of initial purchasers out there who fully specc'd the car when ordering, my own included.
@antspants Welcome and nice shortlist that you have. :) I also had the same dilemma when purchasing my RCF as there was another car closer to me which was in very good condition but lower specification, without the TVD.
I think this is about the best real world example of testing that I found. https://www.caranddriver.com/features/whats-the-diff-we-put-torque-vectoring-to-the-test-feature
So as summarised by the guys above, I think in general day to day driving you won't notice a big difference, but if pushing on or on a track then it will be more apparent.
In my own situation i'm glad that I have it as it means that come resale time my car will (hopefully) be more desirable.
Good luck in your search !