Sonic Shifter Question

[Bluejackets]

Our Team has never used a shifter before and we are considering using the sonic shivers on the new Rhino tank drive system. My questions is..... Is it better to actuate the shifter with the pneumatic cylinders or with servos.

We are very experienced with pneumatics in FRC but would like to avoid them to cut weight but we are afraid the servos may not be strong enough when the robot is up to speed. What do other teams who have used these sonic shifter recommend? Pneumatics or servos?
Thanks for your time and help