The apartment is wonderful. It is very small but everything me and my girlfriend needed. Everything was super tidy and clean. Furthermore the interior has a really nice scandinavian touch to it.
The check-in was super uncomplicated. Raquel, who checked us in is super lovely, funny and provided us with loads of insider tips about the city. The location of the apartment might seem a bit off at first but the better we got to know Porto the more we realized that it's actually in a wonderful and lively area with the best restaurants, bars and shops (at least for us: two 25y. old architecture students). It's called "Lapa". There is a small supermarket (Pingo Doce) approximately a seven minute walk from the apartment as well as some pastelarias (portugese bakeries).
We really loved our time in Porto and our stay at the apartment. I can undoubtedly recommend anyone staying there.