After only two weeks in Tunis (living in an old French/Italian colonial neighborhood), I was suddenly offered the chance to move up to the Northern suburbs of Tunis, to a neighborhood called La Marsa, which is the furthest train stop on the light rail outside of Tunis. I was happy to get to see a different area of town, and so I agreed. Also, this new neighborhood is right on the beach, and is really one of the most stunningly beautiful places I have ever lived.
I walk out my door, and see the sand and beach -- and can hear the ocean waves hitting the shore all night long. It is relaxing and beautiful at the same time.
La Marsa is a much more upscale than my last neighborhood, but it is a bit harder to think about and conceptualize what "upscale" means here -- even in the upscale neighborhoods here, the streets are not much wider than downtown, they are not built only for cars -- the public transportation is still very active here with buses, shared taxis and the light rail. Also, the daytime traffic of people and cars is still crazy and chaotic -- really I don't understand how many people are always out in cafés and on the streets here -- and, there are even people begging on the streets or some who come up to you directly to ask for money. In both areas, women dress quite liberally for the Middle East -- (Tunisian women are very fashionable in general), so it's not clothing that distinguishes the neighborhoods.
The beauty of the beach as your constant backdrop is certainly one difference, but the lifestyle does not seem entirely different here. It is a bit less hectic though, and the streets are not as crowded. I also have noticed that language is also one signifier -- people here like to speak French quite a bit more than you will hear on the street in downtown Tunis.
However, I think that one of the differences is simply that there is just a feeling in the Northern Suburbs of that you were able to "get away" -- it is 40 minutes north of Tunis after all (although a very cheap train ride ~$0.50), it is the time that means it is not really worth it for people to come up here without a reason, so it really is less crowded than downtown, and when it is "crowded," it is crowded with people who live in a richer area...