Scotty, two obvious differences between the auto and the manual - the auto uses a fluid drive, not a solid, so there's some loss in the torque converter. over 70km/h the torque converter will lock, giving a solid engagement, so it's not all bad.
The second impact is the DPF, which filters out the soot. Great idea, but if it fills with soot, it has to clean itself in a regen cycle, which is achieved by firing the injectors during the exhaust stroke.
That being said, my auto gets better than predicted by Nissan. I am not unhappy!