wow, its an issue isn't it! I prob shouldn't be here putting my oar in as ds isn't at school yet and I have absolutely no reason to think G & T will feature in our lives! But I do wonder an awful lot about the whole system, particularly when I hear about Jenk's DS, I can't bear to think of him going through what he obviously has.
As Roisin said the justification for mixed abilty in comprehensive education has been so that children can learn from eachother, and so that any behavioural issues are hopefully spread evenly. However I simply don't these this is enough justification for the system, if the system ends up with such a divisive way of extending the more able.
In my experience of an inner city comprehensive the kids do not EVER learn from eachother or get inspired by eachother. I've simply never seen it happen. As Jenk could testify I'm sure, a more able child is seen as a target for hate rather than someone to learn from, learning being at the bottom of the list of things to do in school, usually!
In practice what this system has acheived is probably good education for the middlers, not good for the top and bottom acheivers, who become disengaged and often disruptive. And particularly for low abilies, sitting at the 'bottom' of the class can be heartbreakingly bad for their self esteem and self worth. Kids always know exactly where they are in the pecking order.
Is it kinder and more productive for everyone if we have top, middle and bottom sets?!