Re the comments above relating to the Durham Road corridor.
The majority of passengers get off between the cenotaph/snooker club and Harlow Green.
How many of those passengers actually live within 5mins of their stop?
You just need to look at the housing in that area, either wedged between Durham Road & Old Durham Road or wedged between Durham Road & Saltwell Road.
Using the 1st area as an example, it isn't hard to see people trudging up Beacon Lough bank after getting off a 21 to see an Orbit, Pulse or Loop trundling past (it used to happen with me way back when, walking up that hill as a kid, with little legs isnt fun - believe me).
It is all well and good having a super fast frequency along Durham Road, but ignoring the residents of Dryden Road, Valley Drive, Church Road or Beacon Lough bank and not having an Orbit extend into Newcastle is strange.
RE: Go North East