Great location in Barrio Alto & overall a good stay! Very convenient in terms of nightlife, restaurants, scenic spots, access to tourist areas of interest, and Metro. Be prepared to walk uphill, but that's unavoidable in Lisbon! If you are a super super light sleeper, this might not be the place for you, as the streets are very busy on Fridays and Saturdays - however I personally didn't have any issues.
The apartment is well-equipped and comfortable, with the exception of the air conditioning. The A/C in our room did work (i.e. we could feel cold air coming out) but didn't seem to be very effective in terms of cooling down the room and we were a little overheated. We appreciated that Luis and Gustavo also left a fan!