A must have
1. It makes from creating a new theme a very easy process, useful for theme creators starting from C5 default theme. Of course, the cloned theme still must be customized to one's needs but that is beyond the scope of this add-on.
2. The developer is an established one, supporting C5 ecosystem by putting dedication in his work. Also, is granted that any question will have it's answer.
3. It's free and it does what it says.
4. Self hosted Google fonts for the cloned theme.