We had a great time staying at the apartment. In my opinion the area is perfect for discovering Lisbon, you are staying right in the center an can reach many destinations by foot. The apartment offers anything you need during your stay and it is perfectly suited for two people who are travelling together but are not a couple. Two things to note when you are staying there:
a)There is a restaurant underneath the apartment which has some quite audible ventilation running until exactly 11pm. At 11:01pm everything was totally quiet but if you like to go to bed at 8pm you might need to use some earplugs
b) The stairs are quite steep, if you are not fit, you might find them troublesome... But on the other hand in this case you might find the whole town troublesome...
For us, the apartment was perfect and we enjoyed it!