Our family of four (13 & 11) loved our stay in Lorenzo's apartment. It has great style, comfort and location. The lofts (2 beds) are a great solution but I wouldn't use it for small kids as the stairs could be scary. The beds were very comfortable and we slept well. A bakery and cafe are located next door so that's very convenient for breakfast. The major sights are within walking distance. We also walked to the train station for our train to Venice. Florence is so packed with tourists that we rather enjoyed not being right in the thick of it.
We picked up delicious focaccia (with salt & rosemary) at canto del raminero, which is just around the corner next to the Santa Croce church. Delicious! We returned one evening for a prosecco and cheese, salami, etc. Very enjoyable, cute interior and very friendly service.
One more tip: make reservations in advance for the major sights (Uffizi, Academia) if you want to avoid long lines. Wow, this city is popular!
I would return to Lorenzo's apartment in a heartbeat and highly recommend it to anyone visiting beautiful Florence!