Honestly, I cannot think of a more pleasant encounter with a host. Marta is SO lovely and went out of her way to accommodate us—meeting us at the bus stop to accompany us to her apartment, taking us to the restaurant she recommended, showing us around the neighborhood, letting us decide on an additional night at the last minute, allowing us to stay later than check out, ...the list goes on. The apartment is perfectly situated next to the art museums and the steps to the upper city. The only things I would change: a larger sofa (our family of 5 had trouble all relaxing together, even with the extra chair we brought in from the bedroom). Maybe Americans like to lounge more than Europeans? :)
Stay here if you are coming to bergamo!