When they use super they have the same speed as always. But they can attack to go faster but the punishment is that the super goes down super fast. Keep in mind that all supers is at least one kill secure(unless you goof really hard) Anyways, what i have learned as a lvl 24 Bladedancer is warlock and titan super can easily shut you down with their own super compared to yours. also if you see a bladedancer that has super on, just run away and let them chase you, like 90% of all blade dancers dont use the attack to boost their speed, or shoot them once with the shotgun( they get like 10% hp left) and then use melee to kill him, you will probably die too, but you will shut down a super.