Check out this thread by @bombsfall from a couple years back for a good idea of how transformative Sim Settlements can be for your experience. 2 sounds like it kicks that all up to an absurd degree & integrates itself into every aspect of the game as well https://twitter.com/bombsfall/status/1072394683366678528
I had an article planned for Quest Log about the original Sim Settlements, so I guess I'm throwing that whole draft out and making it about Settlements 2 now!