We stayed at Nunos place for a couple of days to visit Lisbon and the surrounding areas.
The apartment is very well located somewhere adjacent to the china town section of the city (martim moniz), so expect a lot of chinese-, indian-, nepali-, asian-restaurants and alike nearby.
There's a new neighborhood pizza joint around (not dominos) called pizza wizard, quite delicious.
It's very central, we've walked into the center within 10 minutes.
Additionally the Tram line 28 stops right in front of the door.
The building is quite rustically, the entrance is crumbling, but the flat is freshly renovated, clean, and well maintained - nothing to worry about. No need to get scared off by the hallway, Nuno also explained that they are working on renovating the staircase as well.
One minor note: The staircase is tight, it's a very old building, moving up and down if you aren't well by foot or you have large luggage isn't gonna work properly. It's not easily accessible.

Check-in is extremely simple with a numberpad at the door.
On request we've received a key to lock the door properly.
The bathroom is small and makes efficient use of the limited space, leaving little space to place your washing utensils, just make due with the space in the bedroom.
The shower gave us a constant smell, Nuno is aware of it and looking for a fix. It probably just requires a pipe cleaning.
Just ventilate the place properly and you will be fine.
All in, Nuno is a great host and communicator. He was very nice and helpful with all requests made.
Would go there again.