The spicy pork bul go gi bi bim bap in the hot stone bowl is delicious every time! I just had Seor Ak San's version of that dish and can definitely tell the difference -- Ka Chi's ingredients are superior and thus is the flavour!
The soft tofu and pork soup (featured in one of the Yelp photos) is also tasty.
The standard sides usually leave quite a lot to be desired and their kimchi side is not very good.
Stick to the staple dishes, and you won't be disappointed.