Koryo is the Korean place you all are talking about. I've been there once or twice, and it's probably not a bad place to take people who are less familiar with Korean. Nevertheless, if I'm really up for Korean, I'd prefer to go to one of the less glammed up restaurants over on Lincoln or Lawrence. I feel that Koryo is Korean for Americans. If I recall correctly from my last visit, I felt I knew more about Korean food than my caucasian server.
On another note, my sister went to Koryo recently and experienced delayed service. They explained to her that they had just cut a bunch of staff.
Personally, I'd rather go to some of the other places already recommended.