Any file that you have will automatically add it to your pack when loaded, if you have already downloaded it.
Downloading this while playing any of the add-ons will still add the items to your inventory.
The items given to the player are relatively good for early levels, but are surpassed by better weapons later in the game. Even so, players should not underestimate these items, as they can give a great push early on in the game.
ps3xbox360 Unknown of which of the new add-on causing this problem, (possible system doing this though regardless). In Gun Runners' Arsenal and Courier's Stash, heavy lagging may frequently occur. This happens in a rate that makes the game less enjoyable. Solutions may be entering doors or exiting and reentering the game.(though this may happen on all PS3 systems while playing no matter what as the frame rate may overload and cause the screen to skip for a few seconds and lag to complete stopping and having to turn off the system manually.)