To me settlements bring 2 things to the table: 1 - forget pre-created little towns/villages like in prior fallouts, you get to create them yourself, stores, bard, people, all of it. It has taken up 90% of my in-game time.

There were a few perk-related things in new vegas. I think it was oine perk from a DLC, reset your karma and gave you boosts based on if it had been positive or negative