I heard and saw a lot about uber cabs but services provided by them is not up to the mark. When u book a cab, you will have to wait u till driver calls or cab arrives. There is no option that you can call to driver of the cab which you have booked or wait until driver calls.
You would be surprised to know I booked a cab in emergency and I got a call after almost 45 minutes. After that I driver cancelled. Very bad situation it was.