Unlike the gringo reviewers below, I actually love the flavour and texture of the red bean paste. :)
I have tried all three things that they offer: the walnut cakes, the hotuk and the bing-soo (a.k.a. red bean sorbet). Since the other reviewers have gone in depth of the walnut cake and ho-tuk, I will carry on to the red bean sorbet.
It is basically shaved iced, that is sweetened. Then it is topped off with milk powder (almost like Coffee-Mate), and sweet red beans. I found this combination quite refreshing in the summer! Not only that, I was eating some good soy protein... hey, pretty good for any dessert.
Bing-soo is definitely not for everyone, but if you can break your conception of the traditional icecream and want to try something with more interesting textures, then I highly recommend it.