It's interesting that you took such a liking to sul lung tang without salt. You should have been given a small dish of coarse salt along with the soup. I've never seen anyone eat sul lung tang without adding some salt. There's another delicious and very traditional Korean soup made from a very small chicken (or a Cornish hen) stuffed with gelatinous rice and ginseng. Each serving contains one bird. The bird is stuffed and cooked in broth made priamarily from about 40 cloves of garlic and NO salt. By the time the bird is done the broth is deliciously sweet and garlicy, but flat. A few pinches of coarse salt bring it to life. Sorry I can't remember the name right now but I'll post a followup.
I also first tried yook hwe at Han Bat, and I also love it, but please do yourself a favor and try it at Kum Gang San next time. Their version is superior.