I fear that Microsoft have failed to see the big gaping flaw in this and that is the feedback system itself.
You could be the nicest human on Xbox LIVE, always interacting nicely with the community, and yet you'll still get negative feedback from all of the douches you kill in Call of Duty or Halo claiming that you're hacking.
-
There needs to be integration with game UIs. I'm not sure about DOTA and HOTS but LoL seems to have things more or less figured out.