It adds a lot. Its main quest has original NPCs and is voice acted. The quality is better than some bethesda content, honestly.

It's interesting in that you put down "plots" and then the settlers sort of run them. Kind of like old sim city, where you'd zone this area for residential, that area for commercial, and this other area for industrial. Once you put down a plot, settlers will build it when you have the resources and manpower.

You can also use a preset "city plan" instead of placing stuff manually. I apparently don't understand all the nuances of the mod, because the preset plans typically did better than ones I tried to set up myself.

Some stuff I didn't get right away

• When you place a plot down, you can then decide more specifically what it'll be by interacting with the widget. So if you put down a "municipal plot", you can then pick if you want it to be power, water, caravan services, or whatever. I was just letting them be random at first.
• Plots can upgrade, but they have requirements to upgrade. The UI will often show in red what's missing. I didn't get what it meant, but it turns out a lot of my stuff wasn't upgrading because my defense was too low.
• If you build the little city management desk, you can get reports on what's needed. That's how I figured out my settlement was producing 30 defense, but wanted 120 to feel secure. Woops.
• You can change a lot of game rules and details via that same desk. I think I turned off the disease stuff because that was more annoying than fun, and I set it to simplify materials because I didn't want to micromanage it. But it's there if you want to dive into it.
• You're going to want a lot more aluminum and circuitry than the base game. You need that to build the plot-placing things.
• I think some of the buildings do better, or simply need, settlers with higher stats. You can build "recreation" plots that can boost settler stats. I'm not sure if the game is smart enough to automatically send people to do jobs they have the best stats for. My settlements are a mess because I was just building whatever, but if I did a new game I'd probably be more organized. Probably.

I'm currently stuck because the game wants me to produce 1000 surplus power, and I don't see a good way to do that. There's probably something I'm missing. If I get a shit load more aluminum, I can build a shit load more power plants, I guess.

There's also a whole "HQ" you can build out in chapter 2. It has departments, you can assign department heads, and build out the whole base. It looks like it has some depth, but at this point I was losing interested so I let it just run in auto mode. You can also see where the mod's goal are straining against the limits of the game's UI. It's awkward to do all of it through the workbench UI, but impressive they got it to work.

Overall it's very impressive. I still don't like the base game's combat very much at all, but nothing's perfect.