How to write Ember helper to compare new ember model records with id=null

Hello I have selectbox filled with options from model, where i set initially selected item by comparing records ids with id of currently selected item in relation model :

selected=(eq task.reaction.id reaction.id)

Everything works just fine, till I create new reaction records on frontend which have "null" value in "id" .

when I try to compare straight objects (i do not want to compare them just to find if they point to same ember model object/record)

selected=(eq task.reaction reaction)

It does not work, I tried to write custom helper, but i have trouble with comparing those ember objects, since they are somehow different even while they have same id (screen from chrome debugger objects info http://ift.tt/2lEAaWc)