It depends. If I have to travel from Mumbai to Jhansi, I do not have any Rajdhani/Duronto/Garib Rath on this route. So I will have to choose from among the mail/express trains available on this route. If I am traveling from Jhansi to Delhi, Shatabdi should be preferable, but the overnight super fast trains score over Shatabdi, as I can reach early in the morning and have full day to work on. So it does not have anything to do with the label of the train (Shatabdi/Rajdhani/Duronto/Garib Rath etc.). Travelers choose a train based on the parameters like day/night journey, seat availability, destination reaching time, etc.