I confess I got more out of yoga breathing and relaxation techniques than I did out of the Lamaze method covered very briefly in my childbirth class. But a lot of time was spent covering what happens after the birth, which was new information for me. I'm glad I took it. Also, the class I took was completed in one day. So, look around for something that will fit your schedule - if it's 2 hours for 4 weeks or one 8-hour day. Another reason to take the class: lots of freebies - diaper bag, diapers, coupons, CD with classical music, book, small cooler, foot rattles, formula (which is sitting on the shelf unopened, but I had it in case of an emergency), breastfeeding guide, etc.
Good luck whatever you decide