Ray Allen speed control works fine – never had an issue.

Obviously not designed to do quite the same thing as directly control the rate of trim servo movement, but auto-pitch control is a good device – I have the Trutrak auto-pitch and that does a great job – never have to retrim in climb, cruise or descent (A/P needs to be on though for this to work). So, disengaging the A/P means you take over with the aircraft nicely in trim.