I finally went to Guu. It was everything I had imagined and more. Walking into the restaurant is like walking into a serious-ass party. The atmosphere is loud and boisterous. Everyone is having a good time too. You will as well.
The food is amazing. They have a tapas menu which features all sorts of great stuff. Get the black cod, because it is delicious. Get the seared tuna, for the same reason. Really, I don't think we went wrong with anything we got.
The place is packed. You will most definitely need to line up, possibly for ages. They'll also kick your asses out after 2 hours because the place is so packed. They want everyone to get their turn, which seems fair.
I already want to go again.