CakePHP 3.0 and PHP 5.4

Can someone explain the benefits of namespaces?  And do they outweigh any extra code required?  Is it just to reduce naming collisions?

One of my fears is that Cake might become like Symfony where in every controller/model I write I had to type 4-8 overly-long namespace lines (that I could never seem to memorize), it felt like such a drag.  Love being able to create a new model or controller in Cake in only a matter of seconds by simply declaring the class, a method and often requiring little else (maybe occasionally an App::uses()).  Hoping that won't change too much.  :-S

A really simple Symfony example (it's usually worse than this)...  Urghh....

use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints\NotBlank;
use Symfony\Component\Validator\Constraints\MinLength;

class Author
{
    public $name;

    public static function loadValidatorMetadata(ClassMetadata $metadata)
    {
        $metadata->addPropertyConstraint('name', new NotBlank());
    }
}

Simon.