The reason why I want a D100 if (and it's a big if)its AF especially AF tracking is ok in low light is that D1h is too heavy to carry around for the whole day (and don't forget the lenses)and I can't afford owning BOTH D1h & D100 at the same time. I love the idea but it is simply beyond me.
Since you have both D1 and D100 please do me one big favor, Alan. Go try some AF tracking in low light (say at home with a pet or kid) with both cameras and let me know what you think. Please turn off the AF assist light on the D100 for the test.