Not sure exactly how to phrase this best, but are the DLC's a seperate entity that you select at say the main menu, or do they instantly become streamlined into your Fallout NV world? I've been thinking about buying them, but i've never really been a fan of DLC's that feel very seperated from the core game. Thanks for the help

they become integrated in the game world though mostly new radio stations telling you where to go and start up the quests for the DLCs

plus a message box will appear telling you the DLCs are now loaded after a few minutes of starting

You also get a quest that when you select puts a marker on the map so you can go and start the dlc.

The DLC doesn't work at all. Not correctly anyway.

I highly recommend the New Vegas DLCs! They feel very integrated to the world and the best part is that these DLCs are actually inter-connected in some way. You will hear references from various NPCs to other DLCs/NPCs.

If you get them, make sure to play Lonesome Road last. All DLCs have an amazing story and are extremely well written!