I didn't meet Osvaldo but the communication was very easy. Osvaldo gave us all the information we needed about the best way to discover Porto. Osvaldo was also flexible about arrival and departure times which was very useful.
Location of the flat is perfect, right in the center, close to train station and the metro lines but not too noisy.
The flat is really clean and tidy and fully equipped.
Finally, departure couldn't have been easier as we just had to leave the keys to the janitor.