We went here for dessert last night and found it mostly to be meh (although one of us liked it much…read morebetter than the other).
Bilbao has a thing for, like, really long cones. One of us got one with half donuts/half white chocolate nougat and the other one got a cup of half stracciatella/half whatever the Basque version of 'cookies-n-cream' is. The donut flavor was actually the best one because the cream had a bit of a weird sour taste to it in the other three flavors.
Staff is surly, grinch-like. What is quite lovely about this place is that they had some nice liqueurs for only 6 euros, so we got a couple bottles to bring home as souvenirs. Otherwise, we'd recommend skipping this place--there's a gelateria on every block.