Besides image quality, I've read reports that the AF on the 70-200mm f/2.8 II was faster with the older extender. Is there any truth to this? I'd be interested, since I might actually consider picking up the 1.4x II instead since the image quality difference to the 1.4x III seems to be very little on this lens.


EDIT: I just noticed this thread, but I would be curious if anyone else had thoughts on this.