My wife is hooked on this show. I've watched a few, and it seems that those that constantly bring up predators never make it. Being scared of your surroundings doesn't seem to make for a long-term win.
Seems like food is pretty much the limiting factor. I don't think shelter is that big of an issue, they all get them sorted out pretty quickly, but almost all run short on food.
Seems like a cool show. I'm convinced that they are all being paid, no way they'd do it for the prize alone while providing all the content for free? I sure as hell wouldn't just to say I could do it. Thats a big commitment in time/energy and your life.