Miguel's apartment is in a nice location in the old part of Lisbon. We stayed in the apartment for four nights which was too long. It is really cold in the apartment at night time, there were two extra plankets to keep us warm but I still got the flu from the coldness. But if you travel in the summer months, I don't think the coldness is an issue.
My partner got extremely ill from the tap water, wouldn't recommend drinking it in the apartment, instead buy bottled water from the shops just to be safe.
Next to the apartment is other samekind of smaller units and the half of our stay our next door neighbour was renovating (smashing tiles) from 8 am until 5 pm. It was annoying but if you are not planning on staying in the apartment (work on laptop, be sick etc) it's not a problem. But the problem was that the renovating guy got really drunk during the evening, played really annoying music way too loud and started singing in the shared patio area. He kept going until my travelling partner had to show him with gestures to shut the f up :D
I wouldn't complain this much if the price would be cheaper, since it feels a bit overpriced. The price should be 20-30% cheaper from the current price.