Eduardo is a great host! Even though I haven't had a chance to personally meet him, he was very responsive to the messages, very flexible, and always kindly made sure that everything is alright and that I've had everything I needed.
The place is located somewhat north from the city centre. The way from the nearest metro station is relatively short but quite steep uphill, so people with any kind of walking difficulties should be prepared for that. However, there is also a convenient bus stop very close to the house. Plus, several sightseeing spots with breathtaking views over the whole Barcelona are located very close by, therefore the climb was for me more than worth it. The neighbourhood is a calm and pleasant residential area.
The room itself was clean. It is a very small room, but it has all the basics one requires: enough storage space, a small desk and a chair, enough plugs, its own small lock clean sheets and a towel, extra blanket... There is also a living room and a kitchen available, I haven't used them, but they also seemed nice and clean. The bathroom was also alright. So for somebody not looking for particularly spacious comfort or does not intend to spend a lot of time in the accommodation, this is a great value for the price.
The only thing is that one can hear a lot from other rooms, from the outside, other flats. For me this was not a problem, but if somebody is a light sleeper, they may consider buying a pair of earplugs, but this shouldn't be a huge investment. :)
All in all, I am very happy with the stay. I would recommend it for people looking for a simple stay in Barcelona at a reasonable price.