Before entering The Pitt, Pitt raiders and guards will show you no respect and often call you scab and slave. Following your success in the Hole, their demeanor will change and begin to respect you more and more.
If you choose to free the slaves by killing Lord Ashur and his followers during the main questline, then no more Pitt raiders will respawn afterwards, making the special Pitt raider armors they wear limited in quantity.
If your Intelligence is high enough, they may refer to you as "professor"; likewise, they comment on your Strength if it is high enough. After completing the fights in "The Hole", they may refer to you as "newbie".
The first time Pitt raiders of the generic variant are encountered is in the Capital Wasteland when answering Wernher's radio signal. In The Pitt itself, they are guarding every area except for the steelyard. Generic Pitt raiders are marginally stronger than standard raiders; they also have slightly superior armor and equipment.
The three Pitt raiders sent to pursue Wernher into the Capital Wasteland may be equipped with metal armor, making them somewhat tougher than average.
If you manage to lure any friendly rendered raiders (such as any raider encountered through a random encounter or any raider that followed you from the nearby Satellite Towers) towards where you find Wernher fighting with Pitt raiders, the Capital Wasteland raiders will actually shoot at The Pitt raiders, and leave Wernher alone.