We tried the ddeokbokki, bibimbap, and ddeok galbi. The ddeokbokki was very spicy (that's a good thing), the bibimbap was good (it's almost impossible to mess it up), but the ddeok galbi really wasn't worth the menu price. The menu described it as being cooked with their special sauce, which sounds like it would be really flavorful but it was pretty bland.
I still prefer New Seoul as the best and most authentic Korean food in Madison, but I'd go back to Sol's if I had a Korean craving and didn't feel like going all the way to New Seoul.