I guess this is as much a question related to ember than an API design problem.
When you have non model data, like the count of elements by criteria on an index view or the “last time period” stats, how should it be done ?
On the API side should it be custom action on the closest controller to the data ? A catch all non rest controller with a collection of random data ?
In ember, should it be a service or a custom model for every custom data needed?