Luís' place is at an awesome location, you can't beat that! The flat is nice, but at least when it rains, it gets a bit musty inside - but this might be most places in Lisbon as built-in heating is not usual as I understand. Luís was extremely welcoming and available.
One more thing, the double bed's mattress is quite soft/cushy - for some people it might be a pro or a con. Overall great base in Lisbon.