Marta's place is lovely. The entire street and area is quiet enough to get a good nights sleep but also lively with shopping and restaurants. Close to many attractions. Right by the river. The building is historical and very beautiful. Be aware there are stairs to get to the apartment (about 5 flights I think) and stairs to the bedroom loft area. The apartment itself is big, air con was great, wifi was great, check in and out was a breeze. I would suggest getting a taxi from the train station (if you arrive by train) as the driver knew the area easily and it was not very expensive at all I think 12 euros. Plenty of useful maps and books for tourists and lots of suggestions for restaurants and where to get public transport etc
We had a great time and would definitely stay again when we next find ourselves in Florence.