I have not yet rendered any full movies yet but I did find with the new enhancement "Highlight Healing" has really slowed down and stuttered the preview of my video.
If I choose "Non Real time Preview" It smooths out and is slow as the warning states. Actually if Cyberlink could render my slow mo video as good as it looks in the "Non Real Time Preview" I would be very happy.
My youtube channel====> http://www.youtube.com/user/relate2?feature=mhsn