I've been at Eugenia's house for two nights with other five people.
The apartment is ideal for 6 people (three separated bedrooms, two toilets, a wonderful living room and kitchen), really luxourious, gourgeous and clean, and the position is the most central you can imagine (less than 5 minutes walking to the Porto-Sao Bento train station).
Eugenia was a really awesome host, providing us lots of useful informations and being available to keep our luggage, the morning we arrived, until the apartment was cleaned.
I can definitely suggest a 2-3-4 nights stay here when visiting Porto.