I'm working on importing the Sierra Army Depot into New Vegas. The layout currently is as close a match as possible for the original (only have the first level mapped atm) and if my memory serves me correctly already dwarfs every interior environment in the vanilla games (FO3 & FONV). I'm hoping to add legacy armor and weapons in as well along with workbenches and ammo presses. So far it has been set up with turrets and protectrons. I'm also considering adding eyebot patrols (its been designed with an enclave theme implying in the years since "The Chosen" has been there it has been under new management), a few references to the legacy factions, and possibly a station to create your own robot companion. It will also contain many traps and robotic security units (haven't settled on exactly which ones yet) which will hopefully provide a challenge for even higher level characters and ending with a sizable armory for the successful invaders. Screenshots coming soon.

Hmmm... sounds very tasty. Look forward to seeing your work as it progresses!

Here is a quick top view of the first level before it was populated from g.e.c.k. just to provide an idea of the size of this behemoth. Only has turrets in the map shown and it's been created as close as possible to the original layout.

http://i232.photobucket.com/albums/ee291/j35us_s13/SierraLvl1prepop.jpg

Before I begin, I still want to see this mod made. I love Sierra, but I thought you might want to see.

We actually have a hint at whats been happening with Sierra, but it's fairly obscure so I dont know that most people know. I wont spoil, so here's a link http://fallout.wikia.com/wiki/Abandoned_BoS_Bunker

I thought you might want to know, and it of coursedoesn't mean that the mod needs to be changed. It could easily be worked in for a quest, perhaps. :3

Sounds like fun. You should consider incorporating a puzzle in with the build a bot aspect. For simplicity, I'm thinking a choice of skill requirement or fetch portions.
Good luck and have fun building it. I'll keep an eye out for it.

Thought i remembered seeing sierra mentioned, just means i need to change to the BoS faction, simple enough. Makes me a little worried that they are going to throw it in the next DLC but at the same time I could always just update the nav link if they do, judging from the other areas they are going massively cut the original space anyways.