I passed all 14 exams first attempt with flying colours. I am no grade A student but what I did do was prepare!!! No course will cover everything that is asked in the exams.
I followed Bristols CBT package and used the texts as well, as I prefer to read, highlight ,and scribble my own notes as well. Whenever I had a question it was promptly answered by the BGS staff. Then a couple of weeks before the exams all I did was practice exams. I also searched for any non-BGS practice exams. If I made any errors I would find out what the correct answer was, and find out WHY it was so.
I highly recommend BGS, their product and service are number one in my book. Feel free to pm me if you like.