PLUS : good location, responsive management
MINUS : moldy bathroom, broken washing machine
This unit has the feel of "genuine owner, professionally managed". Check-in process was very smooth (like many managed units, the key is stored at a lockbox nearby - you are given the code to open the box and take the key), and property-management team was very responsive when I messaged them about various issues. Note that if they ask you to fill out the "SEF Form", you'll need to have photos of your passport available to submit to the Portuguese border authority.
The neighborhood was pleasant, and there is a view of the Tigus between the buildings. I found it noisy during the day (as expected), but surprisingly quiet at night. Because it's in a historic district, only registered vehicles such as taxis can enter (an Uber can't). Both taxis and ubers tended to get lost (possibly the streets have been rerouted and don't agree with the GPS). If you ask them to take you to "Chapito Restaurante", they'll be able to find it, and drop you off just a couple blocks from the apartment.
However, if you are sensitive to black mold, DO NOT STAY HERE. There was massive amount of black mold visible in the bathroom, to which my wife is extremely allergic. The experience made her sick for several days after staying. This was compounded by the lack of airflow through the apartment (fans would have been very helpful for keeping the humidity down). It's a historic neighborhood, so this isn't anyone's *fault* per se. But it still ended up being a bad experience for us. Less critically, the unit had a washing machine, but I couldn't get it to work. The property notes said there would be instructions, but I couldn't find any, and the comments from the manager weren't very clear. I eventually gave up and washed some clothes at the laundrymat.
My overall rating is 3 stars, because the mold was a big issue for us. If it's not a problem for you, then this place is a great option.