We had a wonderful stay at Luis's apartment in Porto.
First off, Luis was a great host, meeting us at the train station, riding with us to the stop in Sao Bento, then walking with us to the apartment so he could point out local sights and helpful tips, which came in handy when trying to get our bearings straight.
I will note that the bedroom may be considered a little cramped for some due to the layout, but we expected his from the photos and it didn't matter anyway because we spent most of the time wandering the city.
The whole place was clean and had plenty of amenities, and the shower was really cool -- it could witch between regular shower to jets to rainfall, and could play music and include a light show! Please note that the apartment is split into two rooms and you need to exit into the shared stairwell to get from the bedroom/shower room to the bathroom/kitchen section, but again super easy to get used to.
What sets this apartment is really the location! It is set right on the Duoro River with a beautiful view from the bedroom window/balcony to across the river to the town with the port wine cellars (the view at night is especially outstanding). There are plenty of restaurants footsteps away.
Simply put, this was the perfect place to stay for our trip to Porto. If you are visiting the city and see this listing avaible, I would suggest you book it immediately so you don't miss your opportunity for a few days in a true gem.