There is a big difference in flavor between the Sweet Noodle Sauce and the Soybean Sauce. As the name suggests, the Sweet Noodle Sauce is on the sweeter side, while the Soybean Sauce has a more prominent fresh flavor. I also feel that the sweet noodle sauce might be a bit thicker. I prefer Wang Zhihe's Sweet Noodle Sauce to both, and it tastes great any way you make it. Whether you use it to make sauce popping vegetables, or use it to dip sauce, it is very good. It is even the most authentic sweet noodle sauce for making fried noodles.