In my experience in using them on a Kingcat, I had 2721's on the Rudders and flaps. I would getting jittering on the Rudders. When I switched to 2.4 most of the jittering left the Rudders and went to the flaps. I am using Lithium Ion Duralites with the Powerbox. I talked with Dustin at BVM about a month and half ago and he said that they were switching using 8411's in those areas that I had the problems with. I asked him about the Spec sheet that comes out with the Kingcat at that time and he said that was done a lot years ago. Since I changed out the flaps to 8411's there has been no more jittering. I even tried at one time an amlified lead. I am wondering if the Power box is not regulated to the same voltage as a normal volatage regulator. Anyways I think some time in the future I will probably change out the rudders to 8411's as well. Just my experience.

Alan