Decent service from the support staff and call centre but shameful service from the cabbies themselves. 50% of the time they don't show up, when they do their cabbies are rude, don't have working equipment and will chat on the phone the entire time you're in the cab. For their crap service, smelly cabs, lack of equipment and inconsistency I am giving them a single star.
Go with Co-op. They have been far more consistent and the drivers actually greet you and smile.