We stayed at the San Giorgio for three nights based on a friend's recommendation. They were very responsive to emails prior to our arrival, and sent photos of what to look for when walking to the establishment after getting off the train. As others have noted, it is a bit tricky to spot, but it does match the photos they send exactly. Once you exit the train tunnel, San Giorgio is right in front of you, slightly to the right. A small sign is on the wall.
Again, as others mentioned, this is not a full-service type hotel, meaning the hours when someone is in the building are few. Therefore, you may want to make plans to pay your bill upon arrival, as there is no set checkout procedure and it is likely no one will be around when you do check out. Our phones were not equipped with the proper service to call or text upon arrival, but fortunately those of our travelling companions were. I am guessing the employees of the little store next door must get asked for assistance with this often.
That said, one marvelous thing about San Giorgio is the location. Cinque Terre, and Manarola, are so hilly that it is great to be able to get into your lodging without climbing many flights of stairs and arriving exhausted. We had the very top room, #1, and really enjoyed the private balcony and beautiful views of the vineyards and the sea. This room has a living room area with table and chairs and a sleeper sofa. The bedroom itself is down the hall. The windows have only sheer curtains, but you can close the shutters at night for privacy. The furnishings are minimal but were adequate for our needs. San Giorgio has no stairs and no breakfast.
The internet did not work for the entire time we were there. I later found out that the same was true when the friend who recommended it stayed there. So perhaps there is an issue here.
The San Giorgio's close proximity to the Manarola train station and easy-to-reach location make it a good choice in Cinque Terre. Just be aware that services provided are limited.