Some people feel more secure in the two point or half seat because they have a strong knee on the horse and the shorter stirrup makes them feel more weight into the stirrup irons. Perhaps this is why you liked the canter in the English saddle. Also, the horse makes a big difference. Mac, my lease horse, has the easiest canter in the world to ride. I can canter him all day with great confidence, but my friend's horse, JOker, was hard to canter and I always had some fear when cantering him. Even had a good hard fall from him at the canter when he spooked big time.