Everyone has an opinion about the school and about education in general.
I think that every school has its disadvantages and advantages. First of all, the child should feel comfortable at school. Certainly, school parents choose and they should choose for their child better, but if your child wants to study in another school you need to hear it. Single-sex schools are good because kid more draws attention education, and a schools for boys and girls are good so that the child gets used to the different people and child will be comfortable with both the girls and the guys.
Unfortunately, I can not say for sure which school is better because I am not studied in a single-sex school, but I think the main thing is that the child liked to learn and that she had many friends.