The place is modern, clean, and in a great location. People in Porto are very friendly, so don't hesitate to ask whenever you are in any kind of doubt - most of them speak English very well, and Spanish as well.
If you are coming in fall or wintertime, you should know that it is raining all the time, and it is pretty cold. So, you should ask the host how to turn on the heating, I haven't done that, and tried every single button on the air conditioner's remote trying to turn the heating on, and didn't manage to do it.
Also, you will probably have to check-in and check-out by yourself. Everything is coded, you will get the codes on time, but if you come from a place where it is not common, know that the key is in the mechanism next to the door. Enter the digits you get, and pull the whole thing down to open it and get the key.
Have a great time, Porto is a-m-a-z-i-n-g. :)