I HAVE HAD 2 OF THE EXTRAS AND THEY BOTH FLEW AT THE RECOMENDED BALANCE POINTS WITH THE 120 OS I PUT IN THEM. BOTH PLANES FLEW WITH 2 CLICKS OF RIGHT TRIM PERFICT. IF THERE IS TO MUCH THROW IN THE ELEVATOR YOU WILL GET A HIGH SPEED SNAP IF YOU PULL TOO MUCH ELEVATOR. I SET MY DUEL RATES AT 50% FOR THE ELEVATOR THE SAME FOR THE REST OF THE PLANE. THIS IS MORE THAN ENOUGH TO SCARE THE SH-- OUT OF YOU IF YOU NEED TOO. AT 100% THE PLANE WILL ROLL AT 720 DEGREES PER SECOND. AND BY THE WAY I LOST THE FIRST ONE BECAUSE A BRAND NEW CYCLED BATTERY PACK SHORTED OUT ABOUT 5 MIN. INTO MY FIRST FLIGHT. GOOD LUCK