Medellin is by far the city in Latin America. I was there 4 months 2012/3 and I miss the happiness, the joy of life, the cleanness, the kindness in daily life there. It's wrong to compare but BsArs has the worst service in shops, technology and government I know.
Rosario: I was there 3 times visiting friends and it's a small version of Medellin, green, clean more or less good managed, much better than Macri's work here anyway.