I'm sure there are really good classes, and folks with good experiences.
I never took a class with my first pregnancy because I was on bedrest the week it was scheduled to start, so with my second I wanted to take a class... because isn't that what pregnant people do? I wound up only making it to one class because then I was hospitalized... but that one class I rolled my eyes A LOT. It was for typical pregnant ladies... of which I was not!
Perhaps reading a book would be a better fit- or having personal classes or meetings with someone who can tailor to your needs.
2008-Our Baby Girl, PTL born too early at 30w6d, Fought so hard... Forever Loved & Missed
2010- Lil' Bro, Pre-E at 29 weeks... Induced at 36w6d, Born 37w
2012- Lil' Sis, Super-imposed pre-e at 25 weeks, PTL & GD at 35 weeks, Evicted 36w