Reply to Mixed age preschool class choice: 2-3 or 3-4 year old class?

I'd picked the older crowd. My co-worker who had her daughter attend a preschool/daycare. It was a mixed age group, however her daughter happened to be the oldest one will all the others were like 18months and under. So my co-worker daughter had no kids to really play and talk to and end up having speech delay. The mom had to take her daughter to a special speech class so her daughter can start speaking at 3 1/2 yr old.