In reply to DTE:
I went on the leader improver course quite a few years back and whilst the staff were all v good/helpful in a general sense, I really didn't get anything out of it. It promised to cover aspects such as the mental side of leading (which is where I had a problem at the time) and it simply didn't.
But in terms of getting you started climbing or leading I think it would be very good indeed. The set-up there is quite fun too, though the institutional thing of getting back for tea and biscuits at 5pm or somesuch is a bit strange and makes for very short days on the rock.