My girlfriend and I went on this tour and found it very interesting...especially the wine tasting part of the tour.
There was a great deal of activity there on the night we went..maybe it was too cold for them...although my girlfriend did get some photos of the dam - where the children were reported to have drowned. She had some mist over the dam that wasn't there when the photo was taken.
Also in the workers hut, I had to leave urgently, I couldn't stand it any longer. While the guide was telling us about the hut I had this overwhelming smell of urine and to be honest it was making ill. It was if someone had urinated there constantly and never cleaned it up, it was horrible. No one else seemed to be able to smell it, and when I went back in there to take a photo, the smell had gone.
One word of advice on this tour, if you are tall like I am, you'll have to learn to duck or whack the top of your head on the door frames like I did. Ouch!