I've heard some say that countersteering only occurs at speeds above a particular threshold. I've even heard some MSF RiderCoaches say something to that effect, but you won't find that in any of MSF's written materials (one of our local guys used to say it only worked above 8 mph.). For me, I'm more of the opinion that unless you are traveling at a speed so slow that other actions may have a greater effect, countersteering is the only way to quickly change your direction. At normal highway speeds, shifting your body weight will alter your direction some, but not very accurately nor quickly. Shifting body weight seems to have more of an effect at slow speeds, but it's not very fast, not very accurate, and with little control. Even turning your head will have a small effect, but it's not effective.
People who say they don't countersteer must have a different definition of what it is, or they DO countersteer.
RE: ABS...
If you watch the above referenced video, you'll see that when the wheels reach a point when they are turning at different speeds (just before a wheel locks up...which may lead to a loss of control), the electronics activate some change to try to avoid that happening. It's a lot more about having consistent control than it is about stopping faster or slower.