Fantastic location - you are literally next to the Duomo and all key sites in Florence. Mamo team are responsive and helpful.
The apartment is large and spacious and has many amenities (sans a washing machine). The two flight of stairs (around 40) can get tiring for elderly. Some minor niggles with the living room sofa bed and some humming noise from some place at night (heard only in the living area).
Apart from that it’s a good and a large apartment to stay in.