Looking at the transition guide https://github.com/emberjs/data/blob/master/TRANSITION.md you could try something like:
this.store.createRecord('mega')
tempObject.one('isSaving', function(){ ... });
this.store.save();
Accessing the Store
and creating/finding records has also changed.
Although am not 100% sure those event still exist or will continue to exist in favour of promises?