Aguascalientes is a good place to visit, although I never made it to the Feria de San Marcos itself, which is a shame because I've heard wonders about it. Even though the people of Aguascalientes, or hidrocalidos as we call them, are generally speaking very nice and friendly, it's true that they're not as open minded as the people from Mexico City or the bigger cities, it's a somewhat conservative city. Girls tend to be attractive, they look a lot like tapatias.
I would only add that if you go to Aguascalientes, for touristic purposes it'd be worth it to visit the city of Zacatecas, it's an hour away, is smaller although it's one of the most beautiful cities in Mexico.
I would only add that if you go to Aguascalientes, for touristic purposes it'd be worth it to visit the city of Zacatecas, it's an hour away, is smaller although it's one of the most beautiful cities in Mexico.