Why not have a compromise about schools? Being a Scottish lass born and bred, I don't know much about Grammar schools. I went to a state school but we were "streamed" so had end of year exams. The top 30 best marks went into 2A, the pupils 31-60 went into 2B and so on. I remember there being a 2M who were the slow learners and the lowest 20 of the year - they were perfectly happy and did not have any stigma about being in that class.
I have just retired from teaching after 36 years and while I enjoyed the job most of the time, most of my "wasted time" was spent on the lower ability pupils who knew they were not as academically bright, but had personalities which made them want to be noticed, hence their bad behaviour. I fear for my Grandchildren's generation and my advice to their parents would be to put them to private school (as day pupils) because private schools do not waste time trying out new initiatives all the time - they know the teaching structures which work best, and stick to them.
(off soapbox nw
!) Poppi x