We are in the process of emigrating to New Zealand (Auckland). We have 3 gifted kids aged 8 to 11, so finding the right school is a major issue. It is imperative to find adequate education (not to be confused with pushing the kids beyond limits).
The secondary schools in Germany/The Netherlands/Belgium are differentiated by the capabilities of the kids. There are dedicated schools to prepare the kids for a study at a university (Germany: Gymnasium, The Netherlands: VWO, Belgium: ASO). In our experience this is very adequate for the kids compared with the non-differentiated primary schools: it is considered “normal” to learn fast, the general level is challenging for all kids.
We would appreciate to learn about the experience of immigrants, who are in the position to compare the secondary school systems of Germany/The Netherlands with the one in New Zealand: either in this forum or personal. Private schools are within the range of options.
In addition we are interested in the practical impact on a kid have very good overall learning abilities but no/limited English language skills.
Gymnasium and VWO etc give a much wider range of subjects than is currently available in NZ. If you look at the school websites of some you are interested in and check out their curriculum booklets, you should be able to see how many subject options you're allowed to have. For instance that's why some people choose IB over A levels, because there is a broader range of subjects.
11 year olds can still cope with changing language for education.
If you want personal comments, off forum, you'll to make your name clickable, presumably by adding in an email. I'd be happy to discuss further off forum.
Some NZ secondary schools have mixed ability classes, others stream for ability. For example, at the public secondary school (a large urban school) my children attend, there is an exam before they enter, and the students are then put into 10 boys classes and 9 girls classes according to ability. The top classes are accelerated 1-2 years in Maths and Science and enriched in other subjects. Students can be moved between classes according to how they get on during the first 2 years in particular.
So it sounds like you would favour a school which streams like this. Its a question which you can directly ask the schools of interest.