all the trains between Pune and Nagpur is running on the same schedule. The speed is the same, be it GR or SF or BSP SF or HTE SF or Azad hind or the Humsafars. Except for the Duronto, rest all are having nearly the same journey time between pune-nagpur. This is due to single line between DD-MMR and trains forcefully having to have slack between Kopargaon and Manmad. Nearly 1 hour is taken for covering the KPG-MMR as it has to join the trunk line.
Whereas buses don't have any these kind of restrictions.