It's a well located apartment in central Lisbon. Two things to emphasise are that it is a pain to carry big or heavy suitcases up into it. Second, it is small for any more than a couple.
Saying that, I stayed whilst on a week long business trip. Martin was responsive to my questions and the place is simple, but pleasant nonetheless. Privacy is a bit of an issue, as it's overlooked by other properties, but there as some good blinds there.