in JA doing transition from prop to jet in a slot locked airport require adjustment between routes especially when you are going from dc6b > dc8 in a 7 day schedule format. Having the ability to not go thru 10 pages of route will save a good amount of time.
It is even better if we can get a drop down search for / hour range (like 1-2, 2-3, 3-4.. etc).
The ability to sort the manage routes page by departure time is good, but what would be even better is being able to specifically search for a departure time the same way you search by means of airport codes. Simply being able to search for, say, 1235 for departures at 12:35 would be a huge improvement to the manage routes page.