I turn off mainly for AutoX (where I spun it once - not a nice thing on public roads!). Too many unpredictable things about public roads so, after playing with it off for a while, I now leave it on. Too many times I have come around a fast bend and found gravel or moisture on the road. Once I came upon a flock of peacocks in the middle of the road, if you can believe it!! I am glad to have all the help I can get then.
We also know of a few folks who have lost it, to one extent or another, by gravel surprises. The nannies can't solve all problems (and did not in the case of one), but they do help.
I have too much fun, drive it hard, and love twisty country roads too much. I like my safety net.