A guy at the local photo store said that the AF processors on the D700 and D3 were the same, so it seemed appropriate to compare the more expensive 1D Mk. III with the D700. (A comparison of the other cameras below is more relevant to what I buy, but I'm still interested at what's happening nearer to the top). I was told that the low light auto-focus speed of the 50D and D300s were "close," but I'd like to hear some other people's experiences. The 50D has a lot less AF points than the D300s, so the comparison might be helpful if talking about single-point AF. In a review of the D300 (not "s"), The Imaging Resource said (here), "The Nikon D300 wasn't able to focus in this light without the AF assist light (which is why his eyes are slightly open here), something the Canon 40D did achieve..." I think the D300s is said to have slightly improved low light autofocus over the D300, but I don't know by how much... BTW, is the does the 7D do faster low light AF than the 50D, in single-point mode? How do low light AF speed of these two compare?