I've had my Kamiq for a month now and I have to say that I have pretty much gotten used to it.

However, as much as I think that this is a good thing to have in your car, I would only activate it when driving on the highway as that is where you are most likely to lose focus at some point.
I sincerely doubt that I might wander off while driving on a twisty, curvy road.

I'm also always switching it off, 9 times out of 10 it is just wrong. I do drive mainly on small roads, maybe if it activated at 60mph it would be more useful?