Well, it seems I am not alone on the DS811 flutter/chatter or whatever you want to call it. I have had this JR 8103 promo pack with the R700 and 4 DS811, servo switch, battery etc. I love my radio but can't comprehend the attitude that this rapid, wild flutter of our control surfaces is "Normal" or "Ok".

The first plane I installed these servos in was the H9 CAP 232 Sport. The 811s were perfect even with 12" extensions on the ailerons. They made a low growning noise as a digital will.
I then installed them in a CG Extreme 330 with the 4.8Vbattery, and could not stop them from moving all of the control surfaces 1/4" to 3/8" rapidly in each direction. This plane requires 18" extensions for the tail servos. I unplugged each servo, one at a time and the only time the chatter would stop was when they were all unplugged except for the 537 throttle servo that had remained unaffected the whole time. Syytematic replacement of the R700, battery and switch assembly were no help. I wouldn't even fly a plane like that so I installed 537s everywhere and had no problem.
I then installed the DS811 set on the new Aeroworks 40 sized EDGE 540. this plane requires 12" aileron extentions in the wing and 6" aileron extensions on the radio as access is very limited when time comes to attach the wing. So with 18" of extension on this setup with an additional connector in line, no problems. I just figured the servo couldn't keep up with the control serfaces of the CG Extreme and tried too hard to maintain center. with the resistance of the pushrods and the relatively better leverage ratio over the scale planes control surface weight, they were fine.

That is fine for everyone except for the 3D flier. 3D planes have a lot more control surface area that has more leverage at the TE on the control system than the scale plane does. I think the DS811 servos work great in the scale plane aplications I have tried them in. they are pretty strong with reasonable speed, hold and center very well. I just wish I could use them in my flip 3D.

Regardless of hearing that this is normal and everything will be ok, I will not use them on my CG Extreme or my Flip 3D due to this chatter. Flying loads change and durring a landing, when airspeed and propwash are low, thats the last place I want my rudder fluttering about. I use HiTec servos that are stronger, faster and less expensive untill JR has something in that class that works better than the DS811s.

I don't like having 4 digital servos I can't use on the plane that I want the digital advantage on. I really think JR should do something other than just blow us off with "That is normal. They all do that. It'll be ok when you fly." Well I say it isn't ok if you want the precision performance that you expect from a digital servo. To me an strong analogue servo is better even if it doesn't center completely. At least you can fly that correction. There is no correction for a fluttering, flapping, chattering control surface.