Anyway, the quality of the areas and residential spaces basically goes like this: The lower the number, the higher the quality. Example, in Sector 2, bots are more common and therefore it's well-maintained, cleaner, secure. Sector 5, on the other hand, bots are rarer and therefore it isn't as cleaned and no security whatsoever.
Also take into consideration that most people live in Sector 2, I believe, so it's if you need to live in peace and quiet, you probably won't get it so much. But it's either go for where the majority of people are, or go where you'll likely get robbed.
That's not to say some of the other Sectors aren't nice -- they are. It's something you'll have to decide for yourself.