You can't beat this location!! You are close to a big grocery store, top-rated and affordable cuisine options, and Castelo de S. Jorge (where you get the best view of Lisbon). The area is also quiet, residential, and safe so you can walk around at night without worry. If you're lucky, you'll meet the neighborhood cats.
The space itself is very clean and spacious, so you can expect a comfortable stay. The kitchen and bathrooms are nicer than what we've seen at a popular guesthouse of a similar price in Lisbon, and I have to say, we took some of the best showers at this Airbnb. If you're coming outside of the summer months, I recommended bringing an extra layer because it can get a little chilly at night.
Ernest is also a wonderful host; he communicated with us very quickly and kindly, and I felt well-prepared. Highly recommend this place!