命名空间的最佳实践：在Symfony上，使用（子）命名空间时的perf差异？

Question

I'm building an API and I would ask something about using namespaces on a Symfony2 controller.
Is there a real difference doing :

<?php

namespace My\APIBundle\Controller;

use FOS\RestBundle\Controller\Annotations\View,
    FOS\RestBundle\Controller\Annotations\Post,
    FOS\RestBundle\Controller\Annotations\Get;
use [...]

class MyRestController extends Controller {

    [...]

    /**
     * @View()
     * @Get()
     */
    public function getAction(Thing $thing) {
        return $thing;
    }

    /**
     * @View()
     * @Post()
     */
    public function postAction() {

    }

or doing

<?php

namespace My\APIBundle\Controller;

use FOS\RestBundle\Controller\Annotations as Rest;
use [...]

class MyRestController extends Controller {

    [...]

    /**
     * @Rest\View()
     * @Rest\Get()
     */
    public function getAction(Thing $thing) {
        return $thing;
    }

    /**
     * @Rest\View()
     * @Rest\Post()
     */
    public function postAction() {

    }

Would the alias load everything in the given namespace, losing perfs ? Or will it load only annoted classes, unitary ?