My dc go to s small school - currently 30 pupils over 2 classes. I have at times wished I'd sent them to the bigger school, about 4 miles away.
My thoughts are:
My dc get far more opportunity to do netball/football, as if you want to play, you're in the team. There's a league for the little schools, that the bigger school isn't included in, so our kids do far more school netball or football.
There is a real family feel to the school. Just seeing them hanging around together - no boy/girl segregation, they just play with who they like.
Lovely walking to school, and knowing if a child is sick there will be someone who will take them with theirs.
All the dc in the school get decent parts in school play.
Lots of trips
Very sociable for the parents
Cons
No after school or breakfast clubs, so need separate childcare. For this reason their are a lot of sahm, as not much other childcare availability.
Small friendship groups. May not be a problem, unless you have bitchy/manipulative children in the school.
They are more likely to outsiders if go to other clubs.
Fewer teachers, so if one is bad, the dc are stuck with them a lot longer.