Angle bracket vs. Curly brace values

components.test-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'span',
  value: 'default value'
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<div>
	No value (curly): {{test-component}}
</div>

<div>
	With value (curly): {{test-component value='my value'}}
</div>

<div>
	No value (angle): <TestComponent />
</div>

<div>
	With value (angle): <TestComponent @value='my value' />
</div>

templates.components.test-component.hbs

{{this.value}} -
{{@value}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}