I know someone whose dc attends in Slough. I'm afraid the feedback is not that positive
I'm a big fan of the author's VR books but it sounds as if they do not have any of her own material (yet) for CEM style exams. They use all the books that are mentioned on here anyway but charge £1500 for the privilege.
The parent said they would cover some material in the classroom, meet up weeks later and skim over any homework. The homework lists are usually emailed a few days after the last class. The classes are too long per session but they could be weeks apart too. They also charge their own students for mock exams. The parent feels the course may suit Bucks entrants but feels it does not go far enough to prepare for Berks (especially Kendrick which they are targeting).
In comparison feedback I've had on the big tuition centre in Slough has been pretty good. I've actually seen what both are using material wise and been following the courses over the last year....my suggestion is if you are going for any of the super selectives then the SD course is not for you