I have been using them for the last two years and never had any major issues and wondered some of this experience like
Very good drivers, courteous, clean, well mannered.
Drivers do not drive fast some of times we had them that you can go a bit faster they on the of caution.
Drivers do not disappear after the drop you and wait for your call.
Drivers are available at later hours.
Without any of us accompanying they have used them drop of people at airport, relatives houses and return the car.