At school/daycare/preschool, does your child do best when they are the oldest or youngest?

My child seems to do best when she is in a room full of older kids. She lives to learn new things and is not a full-blown leader. Right now she is in a room where she is the oldest - and she is only 3.5. They don't move up until 4. It's going to be a long 6 months.