Yes, both times. Great for meeting people, but thought there was a bit too much 'sharing' in the early sessions. Later on, fine, but was not very comfortable discussing hopes and fears with a room full of strangers.
Useful topics included; signs of labour, stages, pain-relief options, potential complications, breastfeeding, what to expect afterwards. The session on relaxation techniques was also useful.
Did a refresher before my second which was great, again for meeting people, but also for comparing notes on the reality versus theory. It was amazing how many of us were so much less idealistic second time around. Also useful were tips on preparing the first child for the 'onslaught' of a sibling, as well as ideas on how to reschedule your life to fit in a second child.