How to use `model` in the route?

I don't understand which one of the following ways make more sense in the Ember workflow. What is cleaner?

It is better to have one model like in this code?

app/routes/index.js

import Ember from 'ember';

export default Ember.Route.extend({
  model: function() {
    return {
      categories: this.store.find('category'),
      products: this.store.find('product')
    };
  }
});

Or is it better to not use model at all like in this code?

app/routes/index.js

import Ember from 'ember';

export default Ember.Route.extend({
  categories: function() {
    return categories: this.store.find('category')
  },
  products: function() {
    return products: this.store.find('product')
  }
});

Or are both ways fine and I shouldn't worry about this?