If you get a few minutes then send feedback to VS or even post on their wall. That way you're appreciation will hopefully be fed back to the crew and I'm sure that they would appreciate it :-). I only say that as I don't think there are many current VS crew on here these days and the chances of the operating crew seeing it are pretty slim.
It's a thankless job most of the time but getting some feedback from a happy punter really used to brighten my day.