Computed properties within an itemController don't seem to be updating

I have an ArrayController with an itemController. Both are making modifications to a currentUser’s preferences. When I update the preferences from the ArrayController, anything relying on those preferences are recalculated as expected, but when I update the preferences from the itemController, nothing happens. (However, if I update a property of an item, that property is re-rendered just fine.)

I’ve created a jsfiddle at Ember Starter Kit - JSFiddle - Code Playground, any ideas about what might be wrong?

Huh. As it turns out, I had left out the .[] at the end of the property reference. Everything works now in Ember Starter Kit - JSFiddle - Code Playground. I wish I understood things more underneath the hood, but when I do things as they’re documented, it works fine, I just didn’t catch the documentation for this until now.