Most of these are engineered starches created to have a very low if not totally absent glycemic response. From what I understand, they were originally created for people with the inability to utilize or store liver glycogen (glycogen storage disease); super starches promote steady blood glucose levels even in people who have no liver glycogen (sounds like me towards the end of a race).
From a racing standpoint, the lack of glycemic response in theory should result in enhanced fat burning due to no/limited insulin signaling. Interestingly/suprisingly, this has been supported by scientific data. That being said, these are probably NOT good for recovery nutrition, where a large insulin spike is desired.
I would suggest these products to be used as pre-race nutrition, while normal maltodextrin products would be fine during race as insulin is not as dominant during exercise (if you even have an insulin response) so the likelihood of insulin shutting down fat burning during exercise is minimal. There seems to be real support this these products in the literature, and actually by researching this stuff I've nearly convinced myself to give it a try.