Almost all joysticks out there have some sort of trim wheel though. What I like much better is this throttle quadrant here
http://www.saitek.com/uk/prod/quad.html which could be used for CEM (mixture, radiator, prop pitch).
Although I'm not sure how binky9 trims with a rocker switch (2 state afaik) I'm all for button trimming and heavy use of buttons in general and for as many controls as possible. The reason is simple: easy to reset after a crash if you spawn a new plane.