Super Buu looks like the evolution of Kid Buu. His power will be condensed.
Kid Buu was weaker than Super Buu, though. He just lost all self-restraint and figured the best way to kill people was to blow up the planet and let the lack of oxygen do the rest. He was more dangerous because he was unpredictable, not because he was more powerful.
Socran's Razor: "Never attribute to massive stupidity by someone else, what could be explained by a tiny bit of stupidity on your own part."