I think there is no doubt that the technique discussed above does something to the sugars in the sweet potatoes. The edges are much more caramelized than the rest of the potato and subjectively I do think they are sweeter. I also felt the texture was somewhat changed. Hard to describe but they seem to hold together better while still being very tender. I admit that could be something I imagined. @shain strongly recommending serving the sweet potatoes with some unadulterated tahini but darned if I could find mine.