New Seoul marked my second visit to a Korean restaurant in Madison (Coreana was the first). Compared to Coreana, New Seoul is located in much more modest surroundings with clean but plain decor.
I came to New Seoul for lunch over the Thanksgiving weekend and ordered the kimchi soup. Marked in the menu as spicy, the soup definitely had kick, but more so because of the high temperature of the stone bowl. Accompanying the soup were small plates of kim chi, potato, and other side dishes. The soup was done well and would be a great order for anyone wanting something vegetarian. Most meals on the lunch special were $5-7--a pretty good deal for Korean cuisine.
Service was very good and attentive--it appears to be a family-run restaurant, with the husband and wife working in the front of the restaurant. I saw a lot of Korean customers which was a good sign of the food's appeal.
Compared to Coreana, I'd probably elevate New Seoul to 3.5 in terms of food, but a bit lower for ambience and decor. I'm hoping to go back to New Seoul to try some of the other dishes.