Orange flesh sweet potatoes are hard to come by and I usually end up getting the yellow flesh. Anyway whatever color till it ended up as a sweet soup, maybe the orange flesh perks up our visual and appetite.
The potatoes should be cooked to a desired texture which should not be too soft as they will disintegrate easily and become mushy.
Adding more gingers spice up the soup and warm the stomach. But the amount of ginger must not be overwhelming that it overrides the sweetness of the potatoes.