I think the main reason for me making no progress is that my ability's in the other fields of music, that is hearing the right kind of pitch, feel for ritme, holds me back.

I found that when I practice chord canges a lot by just looking at my left hand (I'm righthanded!), by "teaching" my left fingers, over and over again, where they have to go. Every time while practising for a couple of minutes just on those fingers from my left hand, increased my chordchanges speed.