I had an Eratix 3D, and yes, mine had flutter when flown too fast. Unfortunately, it's the design of the airfoil. It has a very thick wing, and the Aileron is very large, and they're the same thickness from l/e to t/e.
Just to clear things up, it's not a small plane, it's a 54" w/s, and weighs in around 4 lbs. it's not a park flyer sized plane. It is, however, designed for 3D type aerobatics, not for speed. The thick airfoil allows the plane to almost float, and it is very capable when flown within it's design limits. Almost everyone I know that has this plane has experienced flutter when trying to fly it fast, mine would sometimes flutter when throttling up hard, even when the plane wasn't moving very fast.
The hardware that comes with the plane is actually pretty good, however there does seem to be just a slight bit of slop in the controls.
There's a whole thread dedicated to this plane in the Electric aerobatic forum, some very good reading pertaining to this plane.