I really enjoyed my stay in Óscar's place. It is a very good location, short stroll to Old Town and close to public transport (if you plan to use public transport a lot consider getting Barik card as it will give you much better rates than individual tickets).
I stayed in Óscar’s place for a week in the month of September. I enjoy learning languages so I communicated in Spanish. From the time of booking Óscar was very quick in replying to my messages and patient with my broken Spanish :). Before arrival I received messages with detailed directions so I had no problems finding the place. I stayed in a private room and although it is not en-suite it benefits from access to own private half-bath with sink and toilet. The other full bathroom with shower is shared with guests staying in another bedroom. Both bathrooms are finished to modern standards and very clean, also the towels were replaced with fresh ones every few days.
Before travelling make sure to check out Óscar's guidebook of Bilbao https://www.airbnb.ie/s/guidebooks?refinement_paths[]=/guidebooks/263546 tips on local food and culture.