Graça's place is sunny and warm with great views of Alfama and the river. Graça is a good host, very responsive and helpful. I especially appreciated her accommodating my late check-out request and solving a couple of small issues that came up.
Overall, the apartment is a good base if you want to be situated in Alfama and/or close to the Graça neighborhood. Personally, I found the location a bit challenging - most of the things I wanted to do were 20-40 min away by foot, which made it impractical to go and come back multiple times per day. By Uber, it's entirely manageable (not my preference though), but public transit is limited to the tram, which during busy times is about the same speed as walking.
Important to note (and is clear from the description), the bathroom and bedroom are not on the same floor. This was a bit inconvenient for me, as the living level doesn't have a mirror or sink, and is a bit challenging for middle-of-the-night bathroom visits.
I also found the Internet to be unstable and not good enough for work. I had to rely on my cellular connection, which worked out okay. Graça tried to help with this and it resulted in a modest improvement, but was insufficient for video calls or reliable Internet usage.
As others have noted, the ceilings are low. I'm about 1.75m and bumped my head a few times. You can get used to it, but I wouldn't want to be any taller.
The building itself is quite beautiful (and seems to be mostly Airbnbs and other travelers) and the apartment is very clean.