I can't speak to the sushi, and honestly, I probably would never consider having it--I don't think it's a good idea to eat sushi at a place that serves anything else but sushi AND isn't that busy--you risk getting less than the freshest fish.
BUT
The Korean barbeque was outstanding. My friend, who lived in Korea for a number of years and has lived in Chicago and San Diego and LA said that this was the "best Korean I've had since I left Korea." May be a bit of a stretch, but it was actually really good.
If you go, be sure and get the Bulgolgi and cook it yourself. That really is part of the experience. Pajeon was also fantastic. All of the side dishes are made by the family and I give extra Kudos for their Kim Chi. Probably the best I've had.
Why not a five star? This is a place you eat, but I would not call this an elegant experience. And the traffic coming in was slow and steady, but sparse. So no big scene.
I would say if you want a hearty meal after work and want to go out with friends, this is a good spot.