Hey B. -
I 100% feel your pain. I really struggled with finding the right daycare for my firstborn. I'm not going to go into all the problems I had with daycares, but one of the problems I had was what you are experiencing with the 14-16 kids and two adults not interacting with the kids. Also, I had a SUPER large boy as well and I had him put in class with his peer age group (which was appropriate, but he was easily 6" taller than the other kids). However, he was not agile at all and all of the other kids his same age could actually move around better than he could. Anyway, here are some tips/ideas I have for you:
1. Be clear about what the classroom ratio is (students/teacher). I had my son in a daycare where the ratio was 5/1 for infants. However, first thing in the morning, they combined infants and toddlers until they had enough workers in the building. The toddlers ran around in the room and actually stumbled over and fell onto the infants (this made my head explode). They also stole pacifiers and generally just picked on the infants. My son was 4 months old at the time and I eventually was able to move him to a daycare were the ratio was still 5/1, but they NEVER combined classrooms.
2. Be clear on what you saw when you dropped in to observe your son. I know when I visit my child's daycare class (currently 2, almost 3 years old), the kids are oftened in structured/supervised play. But, they are also often in free play where the teacher does sit over to the side and watches them play on their own (this might have been what you observed). However, my daycare does not combine classes during the day except at recess time. Then, the teachers can chat together, but most of the time, the teachers are on their own with the kids.
3. Your son is on the cusp of being at a really great age to enjoy daycare. But honestly, I think 12 - 18 months is a difficult age to enjoy daycare because they don't "play with others" and they can't really get all the one on one time that they want from an adult.
4. We have been at the current daycare for 5 years (my son and now my daughter). But, over the years I have definitely seen things I didn't like and I sat down and talked to the director about each of those things. On the flip side, I have also seen lots of things that I DID like and I have written them thank you notes about it. My take from this is - daycare requires a lot of interaction between you and the directors. You might want to first consider talking to the director before you pull you son from this daycare. See what her response is. I pulled my son from the one where the toddlers were trampling on the babies because the director basically just shrugged her shoulder and told me it was only for about an hour in the mornings.
Good luck!
L.