I visited this place last year. If I could, I'd give it 3.5 instead of 4 just based on the fact that we were constantly ignored by the staff (yes they were busy but come on!!)
Randomly stumbled into this small restaurant and it was constantly packed. We waited too long time to be noticed, seated, order, get our food, and pay (we had to get their attention each time).
The food was really good. We got the beef dolsot bibimbap, chicken gang jeong (the breading and sauce were good but the chicken was weird and tough - definitely not chicken breast!) We also ordered appetizers, including deep fried veggie dumplings & sauteed rice dumplings in spicy sauce - excellent. The veggie tempura basket is large so only order if you're very hungry or many people. Their kimchi is also really good.
Would go again and overall, a great culinary experience but expect long waits.