From the antenatal classes point of view I think it's really important if possible to take partners/birthing partners to them because it's all as much a shock to them as it is to you. And they're more likely to remember something useful when you're not feeling quite your normal self!
I didn't do nct classes last time because I was too late in sorting it all out. From the mummy friends I have made the best thing they said you get out of nct classes (and this is a huge bonus) is the friends you and your partners make. These are soon to be local mums and dads, and knowing people who are going through the same as you in the early days (and still now with DD at 17 mo) is what keeps you sane. Honestly and truly, new mummy friends are priceless. The actual content of the classes is very hit and miss, they can be very pushy about natural birth and breast feeding in a way that makes you feel guitly, and as a mum you really don't need anyone making you feel guilty, you will do that very well all on your own.
I did the nhs classes which sounded better in content, and some of the mums I know who did both said they preferred the nhs ones for what the content and how it was discussed compared to the format of the nct classes. But the nhs ones are very large groups so it's really hard to actually talk to mums to be and make friends.
Like I said I didn't get round to the nct ones because of timing. But I did make great new mum friends who I still see weekly or fortnightly. And I met them through groups/classes like the breast feeding cafes/ baby cafes, open house events, baby swimming classes, library rhyme times etc.
From the point of view of what helps you cope with labour, I did an amazing workshop with both my birthing partners which was done by a yoga instructor and it was called a birthing workshop, I'm sure there are lots of similar events/courses nationally. Because the whole 4 hours focused on techniques for labour and we did it after the antenatal classes, it really helped. You obviously need to know all the details and practicalities and details you learn from the antenatal classes, but there isn't often time to really focus on how to deal with the symptoms of labour.
There does sound something nice about getting to know mums through the pregnancy and then also sharing your birth exoeriences and then new baby experiences. So on that note I can see how nct classes can be great, especially if you vpcan try not to take everything they push on you to heart. On the other hand I know mums who have deliberately not stayed in contact with nct mums because they found it all became very competitive, from when they gave birth and how, to milestones, sleeping pattern etc. It's funny but mums can really get competitive about babies, and I guess when you take a group with similar edd's and age babies, it may just be natural. Still, sounds odd and is weird to watch whe I meet up with nct groups even now.
Sorry to go on so much, I was trying to be helpful, but not sure my confused pregnancy brain has managed it very well!