Nuno's place is well situated in Barrio Alto, next to some great restaurants. It's right next to from Principe Real (one of the trendiest neighborhoods in Lisbon) and is close to a lot of great cafes. There is a grocery store about less than 5 minutes walking that's open til 10PM, and is a great place to purchase late-night snacks/drinks.
Getting to the apartment is an uphill 20 minute walk from Baixa-Chiado and the downtown area - I would recommend the funicular if steps are an issue, but if not the walk itself is gorgeous and littered with things to see around every corner.
My check-in was relatively last minute, but Nuno and Joana (who let me in) were flexible to my needs after a long day of touring!
The apartment is gorgeous! it has a spacious living with the bedroom in the loft area and a kitchen with great amenities. Nuno has also left a guide to the city and the immediate area for your touring needs. The bathroom is updated, clean, and has a great view of the city while showering.
The access-way to the veranda is tiny and requires a bit of squeeze, but it's well worth it for the rooftop views! Definitely spend time up there - it was the best for me to curl up and read a book (as it wasn't particularly cold when I was in town).
Over all, a wonderful stay! I would love to come back again someday.
The ceiling in the loft area is a bit low, so I would just be mindful of getting up quickly. The apartment is also on the 4th floor of the building so the climb may not be for some, but I personally didn't mind it at all.