How to check the success of AJAX request for following chunk of code using Drupal.ajax()
Could you provide more information on why the success function didn't work for you or what code you were using for it? This should work exactly like ajax settings in jquery Ajax since its just a passthrough, so your code would be something like this in your js:

$.ajax({
    url: eventEditFormUrl + '/nojs',
    selector: popContClass + '&gt;div.content',
    wrapper: popContClass + '&gt;div.content',
    event: 'add_event',
    method: 'html',
    progress: {
        type: 'none',
    },
    speed: 'fast',
    effect: 'fade',
    success: function(){
       $(this).html("woot.");
    }
});