I have used a lot of spinners in the past, the best spinner is one of the best out there today. But you should only use the software to help you manually create the spun articles. The automated feature they have is just as bad as all the other automated spinners out there today. They produce garbage that is unreadable and they will be rejected by UAW as well as most other submission services.
So use the best spinner to help you spin the articles quickly, but don't use the automated feature if you want good quality.