I rented the place for 3 weeks. First, Jose Ramon makes the difference with any other house : he is welcoming, helpful, respond quickly to any question, and he will give you advice and make sure you have a wonderful stay. He also provides all kind of trails and visiting guides in his house. He is really a super host :)
The place: it's nice, very clean, it's well equipped with everything you need to cook and to work remotely if needed. It's in the old part of Plentzia so it's very nice and quiet. It's up in the small medieval part, be aware you need to climb up 2 streets to get there, but it's very easy.
It's also a very close walk to beach, restaurants, trails, and to the metro that takes you to Bilbao in about 45 minutes. And to others very nice beaches in about 10 minutes (but you need to walk about 15 minutes to get to the beaches).
If you want to relax in a special place, close to everything, it's the place!