I do think the waters have been very much muddied for grammar schools since all 16 yo began taking GCSEs, rather than O levels and CSEs, with a genuinely vocational strand. Some children genuinely need to begin vocational courses early on in secondary school in order to stay in education in a meaningful way (ie children who are very practically minded, desperate to get to work, and often struggling with the more academic aspects of learning). I do not believe that these children are currently well catered for in any school.
Similarly, from my experience of working in about a dozen comprehensives, I do not believe that in most schools the higher ability children are catered for adequately as in many the staff are all too busy (and exhausted) dealing with disruption both high- and low-level to have anything left for the higher achievers. Furthermore, in areas where there are a lot of lower-achievers, a certain educational entropy seems to set in as schools play a range of tricks to make their school not appear too shite in the blasted league tables.
Also IMO, it is NOT easy teaching either the lower ability (if you expect them to achieve) or the top ability and they keep you very very much on your toes, and nigh on bloody impossible to teach them all adequately in the same classes (as one was expected to do in MFL).
IMVHO, the only children for whom the current comprehensive is truly working is the middle range of ability- it's as though a bell curve has been drawn and an executive decision made not to worry too much about the bits at either end. Numbers seem more important than children achieving their potential.
Ime of working in comprehensives, the children who achieve most often have the strongest parental support, and those who do not the least. Tell me, how is that fairer? The more time goes on, the more I think that the Germans have it right with their three-part secondary system, in which they try to achieve excellence in every type of secondary education.