I recommend this apartment.
Location is fantastic. The apartment is near the train station and bus station. It will be a great choice if you want to visit Siena and if you don't want to walk for a while with luggages. Although the apartment is not in the most popular tourist area, every attraction is in walkable distance. All of famous tourist spots are not near to the train station, so I think this apartment get the best location to accommodate. I like this zone because it is safe, convenient and local. Beside, Pam and Simply supermarket are nearby.
Apartment
I love the bed. It is soft and we slept really well. We can find everything we need in the apartment, such as laundry detergent, extension cord, two towel per person, and well-equipped kitchen. And, Wifi is really fast!
Moreover, I appreciate that they provide two single bed for third and fourth person rather than sofa bed! I highly recommend this apartment to a group of people or a family. But it is hard to adjust warm water in shower room. Overall, the apartment is warm and comfortable.
You can have early check-in by paying $15, if you want to leave you luggage before check-in time. But this rule is not a fixed rule.