I think the DC Animated Universe established that Brainiac can be one of Superman's most effective adversaries. Superman doesn't really have that deep a rogues' gallery, and Brainiac's near the top of the roster.
As for the name, I think it sounds corny to us because we're used to hearing "brainiac" used as a facetious nickname or insult. But that usage is in direct reference to the character of Brainiac. And the fact that the character's name has become a generic term in popular culture says something about its effectiveness, I think.