My Ford Ranger has both, and I have never had a problem with either. The lane keeping assist can be simply turned on or off by means of a button on the end of the RHS stalk on the steering wheel, and it remembers the setting through power cycles. I turn it off on our local road, because its a windy, narrow, unmarked "lane", but I always use it on the better roads and find it remarkably effective. Overriding it when forcibly changing lanes or avoiding obstacles is minimal effort.
The emergency braking has only actuated a couple of times in the last 80,000kms. so hardly a problem. I dont use the car for hard core offroad, but have done many outback tracks and roads, and never had a problem.