there are variables but personally i would never use pneumatic unless circumstances dictate it. as mentioned for throttle stops you can't control the rate of application.

for just shifting a PG transmission i wouldn't even consider pneumatic. use a latching solenoid and if you're concerned about a spike that can be delt with by a diode. the latching solenoids normally only pull about 1 1/2 amps. the transbrake solenoid is just as capable of throwing spikes as well.