"stick snatch" was a nasty thing that happened when the elevator effectively "self servoed " that is you added an input and the thing continued to move in the same direction - overly large counterbalances can easily cause that
Some yokels on their large Extra models , radically increased the counterbalance area -to gain more rudder effect - BAD idea .
I saw one go into lock to lock throw and the pilot did not shut down fast enough ----ka boom!
same idea.
the flat airfoil out of foam is not good at speed-- it bends too easily BUT for rapid fire direction reversals and just fun dodge n dart aerobatics -it can't be beat. one outstanding effect is that you can rapidly pitch to vertical whilst killing power and it simply stops - low mass -- another one is the blindingly fast snap rolls it can effect even at low airspeed
If you ain't into this you will likely dismiss the flat foil as "quaint".