I'm on my fourth baby and have never taken a birthing class. I never felt like I needed one. Our bodies know what to do even if we don't lol. For some people a birthing class calms their nerves and makes them feel more in control. Just do whatever you think will make you feel most confident.
I did it with my first but not my second and I am not doing it this pregnancy. They teach you basics like how to bath your baby, how to put baby properly into carseat, how to swaddled (this was nice to learn), change diapers (diapers are a bit big at first so they show you how to properly fold over), change clothes (not very helpful as changing a doll and a baby with no head or body control is very different but they do try to explain that), they teach you labor coping technics, when you can and cant get an epidural, how to make a birth plan while being flexible, go over csections and send you on a tour of your hospital. That is at least how mine went. Funny thing was I skipped the csection part...and guess what ended up happening lol. As for tours of hospital, you can do that yourself just call hospital first. I work with infants and toddlers at a childcare for years before having my own but I definitely did learn some things...but then if you have a doula and/or help from a relative that has been through this and remembers you can probably handle it without. I wouldn't call it necessary but there are some helpful parts, but yes my husband and I did skip parts. We did the weekend intensive version.
I want an all natural birth, no epidural or pain meds. So because of that i decided to take the class. It has helped me to relax a lot easier than if I wasn't taking the class. Looks like I am going to have a c-section so I won't get to put it to use but I'm glad I went anyways.
I see it as a waste. Everyone staffed in the room will guide you through it.
I took the class with my first. I didn't find it very helpful for me. Though I think its a good thing for partners to feel involved and to be able to relax while asissting. Ive been on both ends of birthing coaching and giving birth. Its a far more scary thing to help someone give birth then it is to give birth yourself.