Nothing bad at all to say about the house itself.
Mainly what was a concern to me was its location in Mouraria. The neighbourhood is a little alarming; I was told it is due to integration politics. Regardless, the alley is slightly dirty and there are always a group of immigrants hanging out there either smoking weed or having beers. At night it can give off an unsafe vibe.
I am not writing this to talk bad about Arlindo's house which is a great apartment (although it is very small - more like a studio), but to share my own experience. Also note that I did not encounter any incidents, but that I felt nervous every time I had to go home. This prevented me a few times from going home either to drop off my stuff, or from going home too late (after having a couple of drinks). All that said, I don't think there is anything that Arlindo can do about it, so again there is noone to blame.