izigame.me

Funny story: I was building the vault and got out of my power armor so I don't waste fusion cells walking all over the place. I was just completely focused on building things when suddenly the vault got attacked and I didn't notice until I heard all the commotion. I ran over to the raiders and found that they had gotten into my power armor and was attacking everyone with it. Amusing as this was, I was also very annoyed and reloaded which lost me some progress. Once I reloaded I knew they were coming and just stood near the entrance and wasted them all.
Bethesda put quite a bit of thought into being able to build your own vault. It's nice that pieces are able to align and snap together by themselves and it's great that they give you a lot of junk in the cave to scrap so that you can easily complete building a nice vault. I like how sometimes it's very forgiving letting things snap together where it would not be otherwise though sometimes it takes way more work than necessary.
What I dislike are little things such as while you're able to build into the tunnel in the back of the main cave, it's not aligned with the grid set up by the entrance and so even when you get things snapped into place it's very tricky because it doesn't want you building so close to the edge of the tunnel and once you do that there's going to be some clipping taking place. Likewise when you build near the edges of the cavern at all there's going to be some clipping because the ground is uneven and girders on the walls will clip through the walls of the vault, but at least the pieces snapping together supersedes that even though it can be very frustrating getting it to align properly so that they snap together. Other things like certain pieces only snap together when you place them in certain ways was annoying too, but ultimately you can do pretty much anything you want to do so long as you take enough time to figure things out. It's hard to properly decorate the vault because the way you hold the button down to pick up items and then you have to rotate them exactly to make then stand up straight is very tedious. I was still able to make a nice vault by placing down furniture, but decorating with small items was too annoying for me.
Overall, building a multistory structure in first person is not a great idea to begin with and while the construction mechanics can be very forgiving at times, it can also be a frustrating experience. With some time and dedication you can make a nice looking vault, but Bethesda could've worked harder to make the building space and the mechanics much more intuitive even though ultimately building the vault serves no real purpose.