I did the 10 day Standard US accent and I loved how specific and tangible the information, instruction and practice was.  Sarah isolates and clarifies particular sounds and explains how to make them.  The work is incremental; starting with single sounds, then words, then sentences and then a whole text.  The feedback is clear and redirects the student to particular sounds and intonation that need work.  I loved that the US accent suddenly became “learnable” .  I am definitely going to do more courses with Sarah.