The apartment is lovely and in a really good location for the centre of Porto, the train station and the metro station. Also 2 decent supermarkets within a 5 walk.
There is building going on next door which probably goes on each weekday between 8-4 but not weekends, I was out all day every day so it never bothered me but if guests are planning on spending a lot of time in the apartment then they'll have to consider this but so much to do in Porto and surroundings I doubt it'll bother most people.