How to Teach IELTS as a Teacher

Alison on Twitter said what do you think of IELTS as a teacher. Do you think it can really show people's genuine ability and then she says how do you teach IELTS speaking to the students? Alison: "I'd say yes and no because I've heard stories ... that the student would speak freely eloquently and coherently with me in the classroom but then they just fall apart"