I only (and I think this is a wise move for anyone) turn off traction control when I'm tracking the car or when I'm focused on spirited driving on the street. Otherwise, if you are just cruising or your whole mind is not 100% focused on the task of driving and only driving, you should be driving with traction control on. It's not like you are getting anything out of having it turned off if you aren't driving it hard and it can save your butt if you hit a slippery section of road when you don't expect it or if something else unexpected happens.
This is coming from a guy who tracks his car regularly.
It doesn't make sense to permanently disable it except on vehicle that only sees the track... otherwise turn it off on a case by case basis.