Puerto Vallarta is a complete 'nother trip, TMK.
Meanwhile if you have some extra time on your hands in Guanajuato State, there is lots to do and a whole lot to see.
You can start with the city of Guanajuato, which is about as far from the airport as Leon in the other direction.
Another 40 minutes or so down the road is the small town of San Miguel de Allende with its extensive expatriate and artistic colonies. There are also a huge amount of historic sites, such as Atotonilco where one of the revolutions got started, and lots of others.
We always took cars, but I understand that there is an extensive and inexpensive bus system that can get you wherever you want to go. Have a good time.