Reservation required on a Thursday evening in the dead of winter? Really? haha at least that's what I was asked when I entered and saw half the tables empty. However they did fill up as the night progressed.
The environment got quite loud, not by music or tv playing in the background, but by other patrons of the restaurant. I felt like it was a shouting match at some point.
Food was good, but not mind blowing. If I had to compare it to another Izakaya, I defiantly enjoyed Guu's environment & food much better.