I would 100% recommend staying at the apartment. The location is unbeatable - it's only steps away from all of the major sightseeing spots in Porto - Torre dos Clerigo, Estacao de S. Bento,
Se do Porto, Igreja de Sao Francisco, Port Wine Caves, Ribeira & Douro River Cruises, Serra do Pilar and Livraria Lello. It's all within a walkable distance. The view from the terrace is actually on Torre dos Clerigos!
The apartment is very cosy - it has everything you might need for a short stay - including wi-fi, laundry machine etc. There is a flight of stairs leading to the apartment and no elevator - but I feel that it's just the price you have to pay for having a terrace with and incredible view. The hosts are very helpful & communicative - thank you so much Martha & Raquel!