Stayed here with my wife for a couple of nights at the start of our recent tour of northern Spain. We've stayed Petit Palace before, & like before, this was excellent. The staff were helpful, the location was superb, the usual quirks of the hotel & wonderful rooms, really. This hotel is very central to a lot of what there is to see in Bilbao. Also, near to the Old Town, where there are lots of restaurants.
The parking is the only slight down side - off site, in a public parking facility with a slight reduction for guests.
Not a big problem, though. And to be fair, there really is no other option. So, can't really complain!