Worst check-in ever. Very noisy, very dark, very hot. Good design. Very clean (as far as we could see in the dim light).
The apartment is very nice but really noisy and gets very hot and even hotter if you want some light from the windows because the lights in the apartment are really really weak; it's so dark that you can't read properly at night, you can't work, you can't shave, even the light inside the fridge is missing. I had work to do, and it was impossible to do it inside, I had to go out as early as 7am to get some work done. I strongly considered moving to a hotel because it was so hot and noisy and dark inside the apartment.
Also, the place is not safe. There are no smoke detectors, no CO detector and no emergency exit. The only exit is through the elevator. The door at the end of the stairs was locked, so you're stuck if there's a fire.
About the check-in; in our last call, Pedro told us he would wait until 9:30pm but he was not there at 9:29. We had to drive around Oporto (get lost a couple of times) to find him having dinner. Pedro made us pay the 30 euros late check-in fee though I really felt that we were the ones who should be getting payed, as we did all the work, Pedro did nothing besides enjoying his dinner. Later we had to try the key on all the doors as the doors do not have numbers (and Pedro didn't answer our call).
If you go in winter, don't have to work, I may recommend it. Personally, I won't be staying here again.