The first version of the Pitt added to Xbox Live was corrupted, causing walls and characters to appear as question marks. Microsoft since removed it and a new file was uploaded, though there are still many bugs in the add-on, like crashes, audio not playing, and certain details that bleed through walls (you'll see it if you look at the right spot).
Overall I prefer the Pitt. It might not have a super awesome story like the main game, and it might have a few bugs, but the new stuff is well worth it. If you've got 800 points burning a hole in your Xbox wallet, then go buy the Pitt.
Other Dude: Heheheh
Dude: DUDE! Did that girl actually start stripping in the Pitt expansion?*
Other Dude: Wut? OMG IMMAGOBUYITNOW!
*There is no nudity or stripping girls in the Pitt, sorry.
-Male figure of the family is named Brad and has been known for the swooning and hot flashes of women globally for the past two decades.
-Female figure of the family is Angelina (last name is hypened "Jolie-Pitt") and has been responsible for many young pre-pubescent males to "discover" their sexuality while watching Beowulf.
-Children of the family Maddox, Pax, Zahara, and Shiloh (and soon to be one, maybe two more) are the luckiest little brats on the face of the planet and we will see them in about ten to twenty years snorting cocaine off of cocktail tables at popular Hollywood clubs whilst not wearing underpants (or pants in general).