True to the Fallout style, but like Operation: Anchorage it is very short, and very buggy.
Like Operation: Anchorage, The Pitt starts with the interception of a transmission as you're exploring the Wastes. An escaped slave from The Pitt called Wherner is seeking help in obtaining a cure for the Trog mutations occurring in the Pitt due to the extreme amounts of contamination in the air and water. If you agree to help Wherner, you travel to the Pitt undercover as a slave.
The Pitt is actually even shorter then Operation: Anchorage. The main quest in The Pitt only takes an hour to finish, and finding all of the Steel Ingots (which is optional) only takes an additional hour. The real highlight of the main quest is that it's closer to a traditional Fallout main quest than anything in the original Fallout 3, as there is no clear cut good and evil path like there are in the majority of Fallout 3's quests. Unfortunately once you finish with The Pitt there's little reason to go back, you can use the ammo press in the Steel Mill, but the Trogs in the Steelyard don't respawn so I never really bothered.
The Pitt, like Operation: Anchorage is a rip-off. It's certainly better than Operation: Anchorage overall, but due to its length and significant amount of bugs it's not worth buying.
+ Morally ambiguous quest line.
+ Trogs can be entertaining enemies to go up against.
+ Fairly atmospheric environments.
- Very, very short.
- Very, very buggy.
- Lack of respawning for Trogs gives you little incentive to return to The Pitt after finishing the quest line.