query_posts based on a meta_key

Question

This answer is pretty covering for this I think:

$args = array(
    'post_type'   => 'brand',
    'posts_per_page' => 999,
    'meta_query'  => array(
     'relation' => 'OR',
        array(
           'key'     => 'wpcf-sorter',
           'compare' => 'NOT EXISTS',
        ),
        array(
          'key'     => 'wpcf-sorter',
          'compare' => 'EXISTS',
       ),
    ),
    'orderby' => array( 'meta_value' => 'DESC', 'date' => 'DESC' ),
);

That should give you all posts with wpcf-sorter-value set first, then the rest, both sets ordered by date.