These days I feel it' more about the commitment and professionalism that goes with the effort to pass this test. In that most other countries cabbies are a lower skilled, often new immigrant job. This comes with certain problems from taking you on the long route intentionally or not, to theft and rape (note: I understand this is completely the minority bad apples). With black cabs you had non of this concern. It was a great service that bucked the usual taxi driver complaints you see everywhere else in the world.