Sugru is nice for little fixes and gimmickry but it hardens quite quickly and irreversibly since it cures into a flexible silicone rubber. It also doesn't stick as well as they claim.
The difference with casting wax is that this material becomes rigid at room temperature so it will be usable for end use items. A better hardening point would be around 70C as in warm contained areas exposed to the sun this material will melt down. It reminds me more of polymorph, a plastic widely used in design schools since it is endlessly reshapeable. It seems to work very well looking at the videos!