My wife and I stayed in Ana & João's place for a few days while we visited Porto. It is centrally located to many great places to visit, both local and tourist spots. One minor thing of note is that the apartment is directly above a Starbucks, which means you will be able to hear any music the store plays since the speakers are in the ceiling (no other store noises can be heard though). Their agent responded promptly to any questions we had and were very helpful.