I stayed two nights at Joseba´s place and I would highly recommend it. It is impeccably clean, the location is great and it has a very welcoming atmosphere. Joseba is a really great host, very communicative (if you want to talk ;-)) and will give you plenty of tips on what to do in Bilbao, where to go and how. And if there is time and you want to, he will even accompany you on a pinxtos-tour around town. I had a great time. Muchas gracias!