Passing JSON data to action as class (explicit declaration)

I got this idea after watching introduction video for Knockout.js library where was shown how easy it is to get JSON data in ASP.

Basically this is the idea:

<?php
class Response {
	/** @var Record[] */
	public $records;
}
class Records {
	/** @var string */
	public $name;
	/** @var string */
	public $email;
	/* ... */
}

class JsonPresenter extends \Nette\Application\UI\Presenter {
	public function actionSave(Response $response)
	{
		foreach ($response->records as $record)
		{
			/* ... */
		}
	}
}
?>

Conditions:

• JSON is checked against classes definitions and if fails appropriate http error is returned
• to action is passed only valid class (never null)

Benefits:

• reduced amount of edge cases
• no JSON parsing (handled transparently) – less overhead in actual action code
• simpler testing
• explicit data contract

Does this seem as a good idea?