Both have alike powers. Only Jubes' is more flashy. Both superheat things, both can do omnidirectional blast/explosion. Only Jubilee can first blind Havoc then blast him to ashes. And Havoc can fly but Jubilee can command her blasts to follow their target.
Edit: He KIND OF can. But not really. I have a comic where he uses his powers from his feet to propel himself like Cannonball through the air. But it was really impractical and he probably won't ever do it again.
Gender: Unspecified Location: REALM OF THE UNDERWORLD
Havok is literally the ONE (ala the movie with Jet Lee), the fucalpoint of his multiverse (whatever that means), his power multiplies by the death of his other selves in diff multiverse and since his the only remaining one thanks to an evil Havok which was killed in Exiles and X-men crossover. He should posses the combined power of all the Havok in the multiverse, that is if he knows how to tap into it. A little too much for Jubilee, I think.