Jeong Won was pretty good for AYCE when they first opened. At that time, the son of the former owner of Arirang and his wife ran the place. From what I've been told, a while back, they got a divorce, and the wife is now the sole proprietor. The food has seriously gone downhill.
All-You-Can-Eat Korean BBQ is the main choice for my company lunches (I work with 7 men... all of our company lunches involve all-you-can-eat grilled meat). Price is good, but the last time I was there, the quality of the meat was pretty bad (freezer-burn was an issue for some of it... and yes, it was brought out to us frozen). Panchan was really skimpy. Noodle Town has a much better AYCE lunch BBQ, if your friend has their heart set on that.