On the overall... I had a really fantastic time at Paul's!
First, the details about the place:
a) The room is actually much bigger then one sees in the photos. :-) Also it has plenty of sunlight as the window faces a really nice quiet street.
b) It is really well located! Really close to the university, city center, supermarkets and it is located near a public transport hub, so mobility is really a plus here. Also, if you enjoy jogging it is actually quite close to the Rhine river so in 4 min you find yourself in a really nice jogging route.
c) The house was always super clean, it was quiet so you could rest and the kitchen is really well equipped. In particular, if you enjoy a good coffee in the morning, they have a really great coffee machine. ;-)
Now, about the hosts. They were super friendly. They were both always available for a really pleasant chat (big travelers, very open minded with rich life experiences). Also they respected those moments where one needs to stay alone to rest or so. All the time they would provide information or help whenever I needed. Also, it actually felt like being home, i.e. one feels really nice, in a cosy friendly/familiar environment. Paul is really funny guy! We had some really good laughs together. I fall short in words to describe how nice and friendly they were! Really thanks a lot Paul and Natalia, I had a wonderful time at your home!
If I go back to Basel, I would definitely stay at their place again. BTW, they both speak fluently German, English and Portuguese.
So, in short: nice room, well located and super nice hosts and the price is really reasonable. What else one could ask. :-)