I have stayed three weeks at Marco's and it is amazing. I would recommend to anyone who want to visit Florence.
Room and bathroom are very clean. Bed is comfortable and cozy. Has everything I need. And if there is anything I need on top, Marco is there ready to help with everything.
Location is good. With good deli (Marco's family) and a lot of good traditional restaurants around. Walking to the city center is around 20 mins and the walk is along the Arno river which is nice.
Communication with Marco is instant. He is very responsive and always keen to help/provide recommendation.