Can't think of a better place to stay for small families in Bilbao!
4 of us - My wife, family friend, teenage daughter and I had the privilege to stay at Inigo's place between July 4th and July 6th.
In terms of location, it is right opposite the Guggenheim museum, across the river, in quieter neighborhood. There are quaint restaurants and coffee shops nearby, and it only takes a few minutes (using the elevators) to cross the bridge to the other side of the river, where many more restaurants and shops are located.
The apartment itself had everything we needed - 2 separate bedrooms, a couch bed in the main area, along with the kitchen and all amenities. Something I didn't realize until we got there was that it also had two separate (and adjacent) bathrooms, which came in super handy. The detailing was quite nice, from the exposed wooden beams to clean updated bathrooms.
And Inigo herself was just an incredible hostess - from providing all the instructions (including electronic entry, which i loved - no key to lose), to recommendations on nearby restaurants, to helping us arrange a taxi back to the airport. Just a wonderful person.
We will definitely look to stay with Inigo should we find ourselves back in Bilbao.