Artur was out of town the weekend I visited so his friend met up with me to let me in, and show me around.

The PROs:
The apartment is absolutely charming and super well situated. Not only near a metro but also just 10-12mins walking distance from the Castelo Sao Jorge. There are also a bunch of convenience stores nearby if you need to get anything. It was also great to be able walk to walk to nearby restaurants for dinner. I highly recommend Solar31, a seafood place 10mins away.
The room was nice, and comfortable, and the bathroom, albeit tiny, had incredible water pressure in the shower. Towels were provided, plenty of shampoo and conditioner available, and even a hair dryer there to use .
Another pro, was the absolutely adorable 1yr old cat, Mia. She was super friendly and a pleasure to hang out with during the short time I was actually in the apartment and not out visiting Lisbon.
Artur was very easy to communicate with and even though I didn't meet him, I had not problem reaching him or his friend.
Only CON: the bedroom is just barely above street level and with 4 or so mini-marts nearby open all night, there are men shouting at each other (or at least speaking really loudly) pretty much all night. Bring ear plugs :)