we were a bit worried at first because our check-in was a little confusing (we were told to wait for Ana or her aunt, and after a half an hour wait told that the key had been deposited in a next-door restaurant), but we ended up having a nice stay despite this lapse in communication. we did discover though, as we were trying to figure out where we were staying, that the upstairs apartment (also rented out by the host and, as we thought, our apartment) is always unlocked and our room key fits a room there as well, which I don't think is the safest practice.
the apartment is in an amazing location, opposite the Pastéis de Belém bakery and close to the monastery and adjacent museum. getting around from here is easy as well, the bus to the city center leaves from right outside the door and the fares are cheap.
the apartment itself is nice, although after a week with four people sharing it (us and an older couple), the bathroom was in a bit of a state. the room itself, as listed and described by other visitors, is quite small and doesn't have a window, but is thankfully equipped with a very efficient fan/AC unit. we were also able to leave the room door open to the next-door living room for extra air, so it was alright.
for the price, you'll be hard-pressed to find a better place--all in all, we enjoyed our stay.