The Hotel Mestas, while hardly as "rural" as the sign indicates, lacks the lowing cattle in the barns flanking the entrance to Casa Florentina. The Mestas has more of a feeling of a small, professionally run hotel. The Casa Florentina is like staying in someone's house.
They are both good, depending on your preferences.
The Mestas also has a beauty salon on the ground floor, where Sra María Cruz Mestas practices her hair-curling art.