Hospitality at some of the bigger events, subsidised training with lots of great trainers, opportunity to win training days (as I did last year - was dead chuffed about that!), discount on various products and services and good chance to meet other like-minded people. Well worth £20 in my opinion, particularly as you get a free voucher for £10 towards training.
Also all their clinics are substantially cheaper if you are a member. They have quite a bit of stuuf in S Cambs and also organise other clinics which are open to all.
