We stayed for 3 months in Magda and Diogo's place, and it was really wonderful. The neighborhood is beautiful and old and delightful - lots to explore within a 10-minute walk. Magda was a wonderful host and helped us with everything we needed. The Conquistador restaurant by the castle is open late and the food and staff are fantastic. We spent many evenings there.
The apartment is a good 25 minute walk (downhill) to the center of town - which of course is uphill on the way back. There are two public elevators on the way to help with the climb, but they close at 9pm-ish, so if you have a late dinner, you can't avoid it. Taxis also aren't able to reach the house itself much of the time (there's a blockade a few blocks away, and the rest of the walk is still uphill). It would definitely be a difficult experience for guests with mobility issues.
The house itself is beautifully, uniquely decorated. We loved that it had so much character. It's comfortable, although not "cozy" - firm couches, firm bed, no real air con, so could be very warm at night. It was stocked with everything you could need, which is rare for an AirBNB. The hot water and water pressure are both very good most of the time (it took us a few days to figure out the hot water). We wished there was a larger refrigerator (there was only a very small one), but there doesn't seem to be room for it in the kitchen, so what can you do?
The place really feels like maybe you live there - isn't full of Ikea furniture, which was a really nice difference from the typical AirBNB. And there were lots of books on Lisbon and surrounding areas, as well as other books (in English!) presumably left by previously guests (always fun!).
All around, and great experience. Recommended for those who like a good walk and a more "local" experience of Lisbon!
Many thanks to Magda for being such a wonderful host!