The space is very clean and has AC (which is much needed in the summer). The beds were also very comfortable, and the apartment is close to the center of town. There is no soap or coffee, but there are plenty of towels.
If you want to access the train station with baggage, it’s best to call a taxi since it’s about a 35 minute walk (with luggage). Also, it’s not clear on the check-in page but it’s not necessarily a 24-hour check in process because you can’t actually pick up your keys until 3 pm. However, you can pay to store your bags at the automatic check-in facility which is next door to the Santa Maria Novella train station.