Lifestyle is more laid back than in the US... regarding night activity (clubbing/going out/etc.), but when it comes to working, damnit, this city works 24/7. The stress invades every single interstitial atomical space there is.
If the activity is even close to what I experienced in Rio, Sao Paulo & Ubatuba even the daytime was "laid back" yes we were busy, yes we worked, but life in general was "looser" I don't know how to describe it, but we wore sandals, shorts and drank lots of guarana, and took at least one football (soccer) "break" in the afternoon.
Dogs were allowed in public places, women wearing thongs shopping in stores, They just seemed to take life in and enjoy it, all the while with very little money to spend.
The hardest thing I ever had to do in my life was get on that flight back to NY.