ORIGINAL: khodges
Some radios have expo for throttle channel. My 9C Futaba has it, and you can make an exponential curve that will give you linear throttle response. My DX-7 does not have expo, one of the few things I don't like about it.
The DX7 has an adjustable throttle curve if you use it in heli mode, but it would be nice if it had that feature in airplane mode.