Uttar Banga extension was a good decision. Dinhata, despite of being an important city, didn't have a train to it's capital Kolkata. Unlike Padatik or Darjeeling mail, Uttar Banga till now has general quota for NCB.
Untiill now, there's another important city in Cooch behar district named Tufanganj that dont have a Kolkata connection. Hope Tufanganj soon gets a new train for Kolkata.