LOCATION
I see that many guests have found the location to be great. We on the other hand did not. This is because we were following the Rick Steves' itinerary to explore Porto and none of those places were easy walking distance from the apartment. They were way on the other side of the river and up the steep hill. My wife cannot walk long distances and needs a wheelchair for long walks. So, that did not work for us.
Public transportation did not work for us. One ticket dispenser did not work with a credit card or cash, and the other had a very long line that was moving very very slowly with folks being frustrated by it.
We had no place to park our car and finally found an expensive garage to park it in, on our own.
The apartment is on the main arterial road with a train station right in front of the building. In one sense it is a great location because of that. In another, from a noise consideration, it isn't.
Maybe this reflects my lack of understanding of Porto since this was my first visit there. But the location just did not work for us.
APARTMENT
There was a smell in the building as well as in the apartment. The sofa in front of the TV is old and worn out and dirty. The kitchen counter has a sticky feel to it. The attached small bathroom has no room for toiletries or to hang closes or towels. The WiFi was not working till I rebooted the router. We had to fiddle with the TV / Cable box to get that working in the morning. As mentioned by many, there is no air-conditioning. There are fans but they are noisy. We could not open the balcony doors to let cool air in due to insects.
The apartment otherwise was clean. It certainly could work for many. It just did not for us. Also, with a few enhancements, many of the issues can be addressed. And with better information and guidance it can help guests on the location front as well.