Had amazing holidays at Porto! We stayed at the apartment for the whole week and were very happy about the location - everything was close to walk during the day and in the evening there were many nice and cozy bars around. The apartment itself is very nice, cozy, well equipped. If you want to cook - you will find everything you need :)
Also there is very nice balcony, where you can sit and enjoy morning sun with a cup of coffee :)
P.S. Just have to mention what many others mentioned before - the only a bit annoying thing is the noise from the bar downstairs - people are singing and loudly shouting everyday (except Sunday - this day bar is not working). This could be an issue if you are not a heavy sleeper or if you have troubles falling asleep :).
BUT our stay at this apartment was so lovely that this bar didn't ruin our holiday at all:)