Cute place in Lisboa! Central to busy night life yet the bed room is quiet.
Would I stay there again? I am not sure. There are at least two points worth mentioning before answering the question.
First, if you have any health issues with mold or if a strong mold odor is off-putting to you, then I would reconsider. The bathroom had a strong mold odor that didn't disappear even with ample ventilation keeping the bathroom window open for a long time. At least one source is the completely decayed of the grout seal behind the faucet.
Second, I am not sure how well the apartment was cleaned between guests.
Based on these two points, I would not stay at Yann's apartment until these two issues are remedied.