We highly recommend the apartment:
First of all because of its great location - you can reach everything easily by foot and all you need is just around the corner (supermarkets, bars, metro-station etc.).
The appartment is very nicely decorated, it is clean and provides everything you need for a stay in Porto.
Eventhough we arrived quite late in the night, Artur welcomed us very friendly, showed us around in the appartment and gave as great advice, what to see and where to eat in the city (he provided a map for us and marked the important points of interests).
You'll definitely not regret staying in this accomadation!