according the guide render: “Gets the singleton instance of the corresponding controller”
if render is invoked without a model, singleton controller instance is reused
I am not sure, if there is a question (left) in here, but there was a change with regards to the render helper in RC2:
Maybe that helps clear things up.
@oneiros, it is reused but it seems to change the scope of the singleton controller which makes it to first call events declared on the singleton controller’s route on the parent with out calling it on the singleton controller and bubbling to the singleton controller’s route and then to its parent.
This has caused me issues explained here: Why do action helpers in a form displayed via render resolve to the parent first instead of the child - Design - Ember.JS