Passed Air Law last week having used AirQuiz. Great site for mock exam practise and good value for money. Even sends you emails to warn you if you're generating too many exams so as not to make you a master of the question bank rather than the subject! The questions seem similar in style to the actual paper, although in my opinion AQ questions contain more choices that can be ruled out instantly, whereas the actual exam seemed to be more geared towards offering four seemingly plausible answers.
That said, one more recommendation for AirQuiz!