Funnily enough, during the week, the new copy of Grays of Westminster Gazette plopped through the door. It contains a piece by Simon Stafford on the D3 and D300 in which he says (and I don't have it in front of me - doing this at the library in Hitchin!) that whilst the continuous servo AF (or whatver Nikon call it) works well with (I think) 9 or 21 selected points, the 51 area 3D AF wasn't especially great when the subject was (a) small in the frame, or (b) a similar colour to the background - it being controlled by Nikon's 1005 pixel AF.