I always thought it was strange to see sims from Sulani walking around other worlds in their tropical beach clothing.
I'd like to see npcs stick to their own world most of the time, but perhaps allow them wander into a different world occassionally. I just think it's unrealistic to see a character from one world hanging out some place else all the time.
I see some worlds as different neighborhoods, but others are more like different countries. I treat the base game worlds as suburbs of the city world. But I treat Sulani, the Japan place, and the German town as different countries. It does seem strange that my Sims can pop into another country just as easily as driving into the city or the countryside. They do it though. lol (I did change one lot in Sulani into a vacation rental though, so my characters can go there "on vacation" for a few days at a time. )
