I made a site with quite a few node reference facets.

It was perceived as unclear when someone clicked on the title of a node (in the facet), nothing was shown for that node, but only the nodes where that node is referenced.

I made a hack in the theme, but I think it could be a configurable option to be able to show some information of the referenced node when it is used in the faceted search.

function phptemplate_faceted_search_ui_page($search, $content) {
  $classes = array(
    'faceted-search-page',
    'faceted-search-stage-'. $search->ui_state['stage'],
    'faceted-search-env-'. faceted_search_variable_get($search->get_env_id(), 'name', 'faceted_search'),
  );
  
//display node information if a node reference is selected
  $itemstxt = "";
  foreach ($search->_filters as $filter)
  {
     $type = $filter->_field['type'];
     
     foreach ($filter->_path as $path)
     {
     
       $label = $filter->get_label();    
     
       if ($type == 'nodereference')
        {
          $value = $path->_value;

          if ($value)
          {         
             $node = node_load($value);

             if ($node) $items[] = $label." : ".l($node->title, "node/$value");
          }
        }
        else
        {
            $value = $path->get_label(TRUE);   
            $items[] = $label." : ".$value;
        }
     
 
    }    
    if ($items) $itemstxt = theme('item_list', $items, "U heeft gezocht op");
  }
  
   return '<div class="'. implode(' ', $classes) .'">'.$itemstxt. $content .'</div>'."\n";
}