I am using them on the heat valves, oil cooler butterfly, and rudder trim.
I looked at the TCW oil cooler butterfly valve and played with it at OSH a couple of years ago. I decided to do something similar. They are using their actuator FWF and so am I. I am also using the actuators for the heat valves FWF.
The rudder trim is based on the spring bias system that Aerosport sells. I replaced the drum-and-cable manual knob with an actuator and bell crank.
The rudder trim actuator with position was this one. I also purchased the LAC board at the same time. Very easy to control with a potentiometer and position indicator wiring is a breeze.
The heat valve actuators I used do not have position, and they are set up to act like regular PWM servos. If I did it again, I would just use the LAC board for each actuator instead of messing around with trying to control a PWM servo. The LAC board makes the 12v actuators basically plug and play with a potentiometer, switch, or button...
For the rudder trim, I was concerned about back driving the actuator. I went with the 256:1 ratio. I think it would work with a lower ratio, and be a bit faster.