Very worth it in my opinion, as you get to make friends with other couples over several weeks, depending on which course you do. When I has my first lo we were part of a group of 8 couples, 7 couples still all meet up 2.5 years down the line. It's essential to have a support network of others going through the same things at the same time, you can share your worries together and realise things are normal as everyone else is experiencing the same. Also the Nct will do local coffee mornings in your area as well as nearly new sales etc, the main website will show you what's going on. I was lucky with my group, most groups get on but occasionally they don't gel!
I now volunteer with the Nct as it helped me so much in the early months!
X
Edit: through my volunteering I meet many mums those who struggle most are ones who don't do any classes, nhs or Nct so have not made a support network. It's so important to have people nearby who are at same stage as you x