I have replaced some of the servos on my timber X and keep getting servo flutter. Can you fly it that way? And are E flights servos just that poor. What to replace them with. Don't have that trouble on any of my other planes

If you have as3x or safe turned on and the servos are moveing just a little that's normal. If the hinges on control surfaces are stiff can cause the same thing.

In addition to what is mentioned above, if there is any real load on a servo while it is just setting there, because of something in the control system being bent or out of alignment, then that can cause a servo to buzz. Something like a pushrod being bent, binding in the hinges as mentioned above, etc. To illustrate this, while the radio is turned on, push on one of the control surfaces, and you will hear and see the servo fighting against the force that you apply to it. Something out of whack in your mechanical control system does the same thing.

If it keeps happening to whichever servo goes into that slot, then it is very likely something else besides the servo causing the problem.

I have changed out the servo doing it and stops the problem. I think E flight just has poor servos on that plane.

That is possible. To isolate the problem, have you checked everything related to that servo, as in the pushrod, connections at both ends, and hinge function on that control surface? Nothing bent, skewed, turned wrong or binding? If everything there operates as it should, then it probably is faulty servos. If there are any problems with any of that, then that is likely wrecking your servos.

Or if you want to use the "shotgun problem solving approach", then find a different brand servo that is the same size and of equal/better speed and torque, and see if it goes bad as quickly.