I did NCT and NHS classes.
I had a very different experience of NCT thank most I think. I didn't really gel with the rest of the (much better off) couples, and had really drifted apart from them by the time the babies were 18 months old or so. The teachers however, were brilliant, very down to earth and did cover pain relief ! We did a c section role play, which meant I didn't panic when I had one and there were 12 people present!
The NHS classes were a lot more focussed on hypnobirthing, minimal pain relief etc. There was a tour of the maternity ward, but I'd been in and out of hospital so much with hyperemisis I was fairly familiar with it!
I ended up working on the local NCT branch committee, which i really enjoyed, and found the wider stuff NCT do beyond antenatal classes very interesting (working with asylum seekers, helplines, campaigning for improved premature care...)
As for longstanding friends - I found them at local parent /baby groups, Surestart and other local groups, as well as NCT "Bumps and Babies" coffee mornings - a cheap and easy "in" to NCT.