This was an incredible amount of fun. We went with a family group of 10, and I rode in the raft with 3 kids (8, 8, & 11) and 3 adults (mid to late 30s) and we put 4 adults in another raft.
Our guide was Jason Michael Webb (who was an absolute blast)! We went on the Upper, and it was the perfect way to introduce kids to white water while keeping the adults entertained and engaged. It was rough enough that you are definitely going to get wet, but not enough that the kids had any fear of falling out (due to the expert guidance of Jason).
My son is already talking about making plans for our next rafting adventure. He's excited to show his friends the pictures that Big Creek takes for you (at a little extra price). 10/10 would recommend (especially if you can get Jason as your guide.)