I bought the 150' kit and my 4 and 7 year old kids love it; so do the adults when we have people over. It was so easy and fun, I am thinking of putting in a 500' zipline. I can't say enough good things about their products and service.
I am a long time rock climber and can say their gear is bomber; the quality is outstanding. Also, the knowledge base from the website and then youtube videos made it very easy to understand.