Until the Arrival and Departure Time and as a result the Total travel time of a train gets reduced, there is no use if a train runs at 130 kmph at 1 section but runs at 100 kmph at other and 95 kmph at other and 70 at other. As a traveller as a passenger when the End-to-end travel time is get reduced by a significant time then we can feel and say that the certain train runs at 130 kmph and then that is pleasant for a passenger. Otherwise no use.
Travel time of Poorva exp from Howrah to New Delhi is same as before. Think of that.