I did my ATPL's with CATS, 3 x 4 day brush ups at Gatwick. exams i broke down into 4 sittings and only needed a couple mornings or afternoons off work. it's possible to do the exams in 2 sittings if you can cram that much into your head. Bristol QB was a life saver when it came to doing the actual exams, not sure how accurate the questions are now, maybe someone else can help with that. But going with CATS meant i could split my exams and stuff into two holiday years with my previous employers. finished with a 93% average and all first time passes.