Serena's place was very modern, meaning most, if not all, of the interiors are new. The main room and bathroom are extremely spacious with high ceilings. The best part is probably the AC. It got quite hot the days I was in the city, and I simply decided to take naps in the afternoon with the AC on. It made my trip 10x better. As for the location, with the massive amount of people, it may take ~15 minutes walking from the station. But the major benefit is being extremely close to the the Cathedral, yet also not really in the crowded and loud touristy area. And in general, you'll pretty much be walking distance to all the other sights in town. Finally, Serena and her son warmly greeted me with water, snack, and even a bottle of wine. I didn't end up drinking the wine, because it was too much for my short stay, but I really appreciate their gesture. I truly recommend Serena's place if you are looking for an awesome place to stay in Florence!