Era's apartment is easily reached by metro from the airport (45 minutes). We were met at the door of the apartment and the reception was great, with a lot of information drawn for us on the map and a bottle of wine as welcome gift.
The apartment itself is beautiful, as the pictures promise, and very spacious. We were pleasantly surprised that there turned out to be a large private and sunny terrace, which wasn't in the pictures! We used it every day.
The bed was very comfortable and the two bathrooms were modern and clean with a nice shower. The kitchen was nice and quite well equipped, although we missed two or three basic items.
The apartment shares its front door downstairs with a bar, which is situated right underneath the apartment (one floor down). Unfortunately, this caused a lot of noise. At night, we could hear the music and people walking about on the wooden floor until around 3 am (and 4 am on Saturday). Then in the morning, we were woken by builders right next door making loud banging noises, but I guess this was a temporary thing.
Also, because of the bar, the living room and kitchen of the apartment smell of cigarette smoke, which probably comes through the floor from the bar below.
If you're into having a drink late at night, the bar below is a great place to visit, by the way! Special place.
The location of the apartment is absolutely perfect, very central and surrounded by nice squares and parks. We explored everything by foot and only took a bus once to go to the seaside.
Although the nights could have been better, all in all we had a great time in Porto.