First on the pros: Maria was incredibly nice and let us check in early at 10am the day of our reservation (we had a flight change). We got to drop off our luggage and take a nap which made the first day much nicer! The flat was fairly spacious and my tall husband (over 6') actually fit under the shower (which from reading many other Lisbon airbnb reviews doesn't seem like it would've been the case in many other places). The location was excellent -- 5 minute walk to the metro and within walking distance to several attractions in Alfama.
On the downside, the apartment appears to be owned by a rental company (LXRoller) rather than a family, so it wasn't really a "local host experience" which we would have preferred. Maria was communicative beforehand, but responded inconsistently/erratically after we got there. We were trying to get tickets to a soccer game and asked if she had any advice, but we never received a response. As a result, we were dissuaded from asking for other recommendations. This was a bummer because getting local recommendations/flavor has been a highlight of previous airbnb experiences! We messaged about a couple of other things in the flat too (such as missing cleaning supplies) and got slow/inconsistent responses.
Also the flat is quite clean and nicely refurbished, but not quite as sparkling and glam as the pictures make it look. It is still a flat in a historic building in a very old city after all :)