Summary: nice place, awesome location, probably a bit overpriced.
I'm a bit divided about this review: The vast majority of the things are clearly positive: The check-in was spotless; the place is new, clean, located in a top-notch building, safe and, best of all, conveniently located in a beautiful area of Bilbao just 10-15 min walking from the city centre and 5 minutes from the river, so if your thing is running, you couldn't find a better place!
What are the downsides? The place is clearly made for renting, not for living, as some things are beautiful but not very functional. Just a couple of examples, the office/desk only has one socket: either you switch on the lamp or the laptop, but not both; the table lamp in the living room is big and the moment you touch the lamp shade even in the slightest way, it will destabilise. We've been in multiple Airbnbs in Bilbao and because of these small details, we consider that the place is a bit overpriced for what you get but, of course, this is subjective.