As usual, a complete load of crap being talked about these question banks. The fact is that they are all the same, and draw mainly from the big load of Italian feedback that was released a few years ago.
People say that Bristol is very accurate, true, but so are all the others. I used Bristol and FlyingExam when I was doing my exams last year, and found them to be very similar, both in numbers of questions and content. Prefered FlyingExam in the end as they have divided the question bank into different topic areas for each subject, the Bristol question bank lumps them all into one category.