I agree with pretty much everything that has been said so far.
Me, too.

I especially feel strongly about ability grouping. I also believe that mixed age classrooms in general are better.
Agreed!
My other thing that I feel strongly about is teaching beyond academics. How will a child living in poverty ever learn to manage money for instance? How will a kid who sees adults in their life making poor choices daily ever learn to be a good decision maker? We need to spend a lot of the day teaching real life skills to children, especially those children who are not learning it at home. IMO, this is an important part of breaking the poverty cycle.
Absolutely! Excellent to teach life skills such as financial literacy, planning, weighing outcomes, decision making. That said, fortunately many children may still learn these these skills and concepts at home, from their parents.
We need to teach all students to be better critical thinkers. To understand and interpret statistics and navigate a world full of advertising and politics. We need to teach logic rather than just textbook math.
Yep!

I would also argue that the assertion that less able kids benefit and so do more able from mixed ability classes sounds ridiculous to me... I honestly think ability grouping leads to better self esteem and more effective teaching of all abilities.
I believe these links provide the research/findings/facts which support this:
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http://www.casenex.com/casenet/pages/virtualLibrary/gridlock/groupmyths.html,
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http://www.gifted.uconn.edu/nrcgt/reports/rbdm9204/rbdm9204.pdfOK, said my bit. Not that it will make any difference.
Well, it just might... especially as other parents find areas of agreement, and support grows for these ideas.