I choose to use these servos on my T-Rex 450 for a few reasons. They fit in the helicopter perfectly, they have metal gears and they can handle 6 volts.

Metal Gears:

If you have a T-Rex 450 and are currently using HS-56 servos or any other small servo for that matter, you are probably very familiar with replacing gear sets as they seem to break every single time you crash. The HS-65MG servo takes care of the pain as it comes with metal gears that survive most crashes. There is a small disadvantage though, if you crash hard and at a bad angle, a servo can end up tearing up something else, such as your main frames! However, I have crashed by T-Rex 450 countless times and have never seen this happen. In addition, I have over 1000 flights with my original HS-56 servos and they’re still going strong without a single gear replacement!

Faster, more torque:

HS-65MG servos are slightly slower than HS-56 servos, but they have a lot more torque. The extra toque translates into a feel that makes you think you have more power. My T-Rex SE came alive when I started using these servos. The response on the cyclic is so fast and reactive that it seems as if I would have added more power to the entire helicopter!

Servo Specs:

0.11sec/60° at 6V
30.55 oz-in at 6V