The best part about this apartment is its location - right in the center of the old town, walking distance to sites, bars, restaurants etc.
Be prepared for a climb - the house is on a very steep street and the apartment is on the 3rd floor so it's a good little workout :)
The apartment itself looks exactly like the photos and the beds and shower are good and comfortable. There's also a tv with tons of channels in English (and other languages).
The only little con is the entrance door to the building is not of the best quality so you've got to play with the keys a little to be able to lock it, but other than that it's a perfect base from which you can explore all of Porto.