I had a very similar experience to @PurpleBananaSmoothie
I would say they were very focused on a textbook "natural" labour - which I know very few people had. Our instructor gave several horror stories about Pethedine so I was scared to take it. However, at the time, I was in a lot of pain and it was the only thing they could give as I wasn't dilated enough for the epidural.
It gave me unrealistic expectations as to what my labour would be like (i.e. contractions start, have warm bath, count etc) - mine was nothing like that, I had Hollywood waters breaking and contractions going straight to 3 in 10 (despite only being 1cm).
I would say I genuinely learnt more from watching One Born Every Minute than I did in NCT.
However, having the support network once they were born was invaluable. You are going through it at the same time as others. One of my friends put it as £300 to get 7 phone numbers - which is true. It was great in the early days when you need to get out of the house to go and meet for a walk/coffee etc. Unfortunately, our group isn't close anymore as lots of them moved away. However, I know other people that have super close NCT groups and they go on holiday together and everything! I just wouldn't put pressure on yourself that these are life long friends, becuase I think it really depends on the group.
Where I live there is a baby group for under 1s and it happened that there was a baby boom around the date my DS was born - I've made really close friends from that (to the point we hang out every week, had a joint birthday party for the kids, go out for meals/drinks), so I disagree with the PP that said you don't make friends at other baby groups (having said that the baby sensory class I did was so cliquey).