Andrea is really nice and helpful. I think this room is the best, it is the most private since its at the end of the hall; the window faces the trains and the moon at night, its really beautiful. If the noise disturbes you, the windows are sound prove so it won't be a problem.
Location is great, in front of the house you have the trams and a lot of options to move around Rome.
San Lorenzo is the perfect place to be near the center but also get to see another side of Rome, with out many tourists and it has delicious local restaurants and gelatos, living there you can enjoy the touristic and the local side of Rome.
P.S. THE BED IS AMAZING, super confortable!!
Recommend it!! :)