Thanks for the comments, shortstripper. Perhaps I have particular difficulties with control sense reversals: I guess everyone has different aptitudes and experiences. I didn't have difficulty with the foot throttle after a little bit of practice, but slight variations in the mechanism on different types might make a huge difference to the ease of control: I was on the latest and greatest Pegasus Quik GT, which seemed a lot nicer to fly in many respects than some older types.
Your decision to quit while ahead sounds like the mark of a good pilot.