Mageblade: 7th and 8th level spells (though these are differently organised and weighted than the core lists.) More magically versatile by far.
Duskblade: nearly everything else, I suppose. Can't fully remember, right this moment. Good BAB f'rex, right? Oh, and more low level spells per day than a SORCERER. *vomit*
Yeah, it's no contest. Blame the Mage Blade for being balanced, I guess.
Also having access only to simple spells (barring feats), which for AU/AE, make the Duskblade's list seem not as bad as when people typically compare it to a wizard's, for whatever reason.