This post is almost 2 years old, so a lot has happened in between. As an update, my son was in ESF K1 in TY, but was then fortunate to get into Reception of another through train school which happens to be fully IB. We have moved since then.
Just yesterday my son told me he loves his current school, but not his previous school. After being in various schools and gaining a deeper understanding of IB, I come to realize IB is more an outline and philosophy then an actual solid academic program. It takes the school and the teachers to form the structures and fill in the blanks.
Not only are the teachers playing a vital role in the IB program, the school too is important in its monitoring and execution. Just like back home when all schools in the city uses a similar program directed by the Board of Education, the quality of education differed from school to school and teacher to teacher, and of course, how the parents role model and raise the kids at home.