Setting up a curve in your throttle responce (in other words this is reducing the the servos response away from a strict proportional response) is a tool that is used by many helicopter flyers and certain types of 3D flyers but for most of us its is not normally neccessary or commonly used.

The comments above about the older manual rotary pot type of trims versus the current push button electronic type of trim is pretty much moot. This is simply because that type of trim has not been used by any manufacturer for some years now and its certainly not some sort of plot by the manufacturers.

Genes description of how he sets up his throttle and kill switch is what most of us do these days and the Kill switch setup if you select the right switch is far better than the old method of forcing the pilot to take his thumb off the throttle stick and attemting to find the throttle trim. This is fine normally but when the engine needs to be shut down quiickly (and yes this happens) especially near the pits the electroic kill button is far better.

Its for this reason I always make sure my students do properly get their throttle and kill buttons set up and are practiced at using them. By the way I beleve all modern radios do include the kill button feature except possibly some of the toy variety type transmitters.

John