Negative-With those who build grand houses/lots how will this effect the loading time? Common sense tells me it will take longer which could put a stifle on creativity because I do not want to be waiting for LONG periods of time just because I went and built a sector with large grand mansions.

The positives are- This allows for bigger richer more complex worlds than we already have. Secondly loading a world up in Sims 3 was agonizing with it taking around thirty minutes for at least me. With it no longer needing to load up an entire world this will probably cut that time considerably. The biggest reason of all! With districts it means Sims can be concentrated more in one area thus giving a more lived in feel. It already has been confirmed that when clubs are released they will not be the empty ones found in Night Life. This is GREAT.

The negatives are-Loading screens but we must remember that these districts are large and are not just one house going to another lot plus they are going to be short loading times around thirty seconds (this could change with EPs however and become longer). Other than that I really can not think of any more because we know so little. We have to remember because of this we should not react negatively. My biggest concern is that these loading screens will remove the immersion but we again will have to see.