it's fine within the confines of the same building, and all the pupils wear the same uniform!!
What do you mean?
As I have said, both my DCs attend a pretty much true comprehensive, so while it is their individual experience i am drawing on, at least it is experience of the comprehensive system,. not a grammar one.
Yes, certain subjects are set - very few in Y7, quite a few by Y9, back to core subjects only in Y10&11, not set for A-levels - but there is mixed ability teaching in some subjects (and all option subjects for GCSE & all A-levels) all the way through. Yes, thee will be some fellow students - of all abilities - that DD and DS have never been in classes with, but that is random, not because of their ability.
DD in particular is in option classes with pupils of very low academic ability, as well as in setted groups with all the high flyers. It hasn't affected her progress in any subject - grades very very high across the board, and she will choose 2 subjects she is currently not in sets for for A-level. Classroom management and discipline are good, well backed up my senior leadership.
There is no NEED to say that grammar schools are 'the answer', when excellent comprehensives are out there showing what the answer can look like.