Canon's Chuck Westfall claims that the 5D2 has a better AF system than the 50D/40D but it is not the same and lacks the multiple cross sensors across the frame. I haven't used the xxD series so I can't comment on tracking performance.


I have seen comparisons on the www.dpreview.com forums between the 1D series autofocus and the 5D2. The 5D2 fared exactly how you described: less than stellar to be sure.