I would have given this place 4 stars; however, there was an issue with some false advertising regarding the air conditioning when I booked. Checking their listing now, it appears that they fixed this and do not claim that the unit has AC anymore. If I were to visit Lisbon in a cooler time of year, I would stay here again. I would not stay here again in the summer.
Pros: Fantastic location in central Lisbon, easy access to sites, transportation, food, and nightlife. The managers are very friendly and very attentive. They were easy to talk to and got me what I needed when I asked.
Cons: No air conditioning. Not a problem if you know what you're getting into, but I did not since the description when I booked said that the unit had AC. No AC means that the unit got hot in the afternoon, and the windows had to be kept open at night to cool the place down. The shower was a little temperamental in terms of getting it to stick on a temperature that wasn't freezing or scalding, but I eventually got the hang of it. Couch bed definitely sleeps one adult, not two (unless they are small / like to spoon).
I was working (via internet) from the unit in the afternoons so the heat (while not terrible) was not ideal. The apartment is next to a lively nightlife district so the streets get pretty noisy around 4am when people start to head home. I was able to remedy this with ear plugs and sleeping aids, but I remain disappointed since I specifically booked this place thinking that it had AC. The managers were very apologetic when I brought it to their attention and asked what could be done. Short of them buying and installing an AC unit, I don't think much could be done.
Again - the managers were very nice and seemed to sincerely want to help, but with a thing like a missing air conditioner I really don't know what could have been done. Other than this, everything was as expected with the unit. Would stay again from September to April, but not in the warmer months. Special thanks to manager Rui who was very helpful during my stay.