The guesthouse is very close to the central station and metro, just be ready for a few minutes of uphill walk (but that's just how Lisbon is!).
The shared areas (kitchen and dining room) are spacious and well equipped, the bathrooms are quite tiny but there's a good bedroom-bathroom ratio (3 bathrooms, 2 of them with a shower, for 7 rooms). Our room was very comfortable.
It's a quiet area and you won't be disturbed by noise.
The self check-in process is super easy and it allows you a certain flexibility in check-in/out times.
There's no heating in the common areas, if you're not used to it you might want to bring an extra sweater. There's air conditioning though.