I had a fantastic time staying at Luis' flat and was excellent host. I had a late arrival (around Midnight) and Luis was highly communicative before and during my travel, meeting me at the flat to show me around. The location couldn't be better, overlooking the Douro in an extremely authentic building, perfect place to head out from and relax in the evenings.
The only thing to note is the banks of the valley are quite steep and you start each days walking at river level so metro stations, restaurants etc could pose a challenge if you struggle with inclines etc
Otherwise I have no complaints, highly recommended!