I think you are misunderstanding Mike's auto-group scheduling feature.
The scheduling itself is not 'heuristics'.
It is the _composition of a group_ that has a heuristic default. (We use the 'tty'
to act as the grouping)
But that can be changed: the cgroup interfaces can be (and are) used by Gnome to
create different groups. They can be used by users as well, using cgroup tooling.
What the kernel does is that it provides sane defaults.
This is not some kernel heuristic that cannot be modified - which was the main
problem of the O(1) scheduler. This is a common-sense default that can be overriden
by user-space if it wants to.
So i definitely think you are confusing the two cases.