Kazuya,
That is excellent. I was worried that fixing his head would look unnatural but you are right; it looks much smoother and cleaner. I'll keep this in mind for next time.
Just as a note there is also one frame (3) where he looks away slightly. its only a one pixel shift so its not as noticeable as the look toward the camera that was in frame 6. Looking at it it just flashes by.
I was wondering if it was worth extending it to two frames and making a 2 frame one pixel shift towards. I'll make the adjustment later and ask for some feedback.
Cheers,
Steven