I really, really cannot comment re schools outside my ken, and evidently not regarding the aptitudes of any DCs whose parent were considering moving into the 'right' catchment: horses/courses, etc.
But Thornden does it for us as we have 2 'B grade DSs', with the odd flash of A, and I wanted a comprehensive feeling school which didn't make a deal about setting (they only set in Maths and MFL for mid Y7- end Y9, when they 'set' according to exam group trajectory, and even then, they 'personality profile' DC so you can get a higher graded DC in a middle class than a lower graded DC in the upper class as they've deemed one works better at 'top dog' and the other performs better when 'pushed' by 'better' DC).
So, far (end of Y7 and 9) it's working for us!
I confess that I may have under-estimated DS2, thinking he was way less able than DS1 thus chose a school in which the 'lower sets', such as they are, contain the less able but not the 'can't be arsed' chair throwers (Thornden is vair MC)- however, DS2 is doing rather better than we'd hoped- maybe, just maybe excellent teaching??