A hafted weapon, but one where you can only hold the middle? Rubbish.
The sword has always been the primary individual weapon throughout most of history for good reason- it's simply best at the job. In large groups, pikes might do you better, though many who study Japanese warfare think that Samurai would have annhilated pike formations.
But really youe options with Maul's weapon are extremely limited. Most of your skill is put into making sure you don't cut you're own head off, you have a crippling weak point as people aim blows towards your hilt, you can't get the advantages of hafting because, as I say above, you can only hold the middle, and though it may look good for fighting two opponents, it doesn't take much to notice that once you block with one side the other side is useless.
It doesn't matter, of course, because it's all fanatsy and it looked gorgeous. But some people now seem to think it would be the ultimate weapon in 'real' fighting... uh-uh, guys.