Birthing classes

I'm just curious how many of you have done birthing classes and what your experience was with them. Is it worth the money to do it? How far along were you when you took it? My hospital offers a 7 week class for birthing, infant care, and breast feeding that I'm thinking about signing up for but wanted to get some opinions first. I'm currently 24 weeks and was thinking about starting in March when I would be 30 weeks. Is that to late to start a 7 week course? Thanks for your help!!