There were 12 of us staying in this apartment over a weekend in January, and while that sounds like it might be cramped certainly didn't feel that way. It is in a fantastic location close to restaurants and night life, but not too close that you get disturbed by late night revellers returning home.
Communication with the host prior to arrival was excellent. During the stay we had an issue with the electrics tripping once, but this was resolved very easily over the phone. Our wifi also cut out on the first night, but again one phone call was all it took and someone came around while we were out and it was fixed by the time we returned from the day's activities.
Overall I definitely recommend a stay here and would certainly stay here myself if I visit Lisbon again.