Funny, I added a switch to my 07 Taco to turn the ABS off. That thing, if a wheel slid just a tiny bit, it would completely release the brakes, then maybe start trying to apply them again... some time later, maybe miles down the road. OK, not really miles, but literally, several hundred feet.
4Runner's ABS has never been an issue on road, and it seems that turning on MTS or ATRAC either disables it, or makes it extremely unintrusive, to the point that I can lock wheels in sand/dirt and dig in to stop.