I started the new DLC last night after the kids went to bed.
You lose everything except for some good items like the Vault 13 Canteen.
Even though I am playing in Hardcore, the typical loss of H2O, Food & Sleep is not acting the same.
All I can say is collect the typical junk for making Weapon Repair Kits, as well as collect stuff for the recipes as well as the new Sierra Madre vending machine.
DO NOT FORGET to look behind doors when you open and enter a room. I have found some good stuff hiding behind an opened door.
You will be able to find and make enough weapon repair kits to fix up the holo rifle into a decent gun. Use the Police .357 for the speakers. Have found but haven't yet used the automatic rifle.
Only way to get back health seems to be with stimpacks, water and food. sleep does not work.
So far a fully charges (75+%) holo rifle is the best weapon against the ghost people. A "clean" knife for the final kill.
Only thing I don't like about the new DLC is the constant dark look and feel of the new environment. I have collected & made some ghost site, same as cateye, but haven't used it yet.
Watch out for trip wires, frag mines. Explosive skill points of 30+ is recommended?need to disarm some of the hanging grenade traps in order to collect the frag grenades.
I'm so glad I took "pack rat" as one of my perks, which causes everything at a weight of 2 or lower to drop in half. It was really a big help for carrying sufficient ammo like to 50mm/MC cells in The Mojave. In Sierra Madre it allows you to carry twice as much small stuff before off loading to DOG or cashing in at a machine.
DO NOT consolidate any clothing you find in Sierra Madre. It does not help the Vending Machine [return] value you get in Sierra caps. Opps.
I'm not sure if I like the new DLC. It feels too much like starting over rather than building upon whatever achievements and weapons collection you had developed in The Mojave.
Well that's it for now.
Axx