No matter how awesome the vibroaxe is, you only get to make one* attack per round. Teemo made one for Lowrhhick and he ended up owning it after some nasty business at the palace. Sure, it's gruesome. But the wookiee gladiator demands blood, so I give it to him in buckets. Anyone have a towel?
I have found two different pictures in the rule books where Lowrhhick (or some other Wookiee outfitted much the same way) is clearly using a BD-1 Cutter Vibro-Ax in a one-handed manner. Of course, he's not swinging a PAIR of vibro-axes like that, but he is clearly using it one-handed -- which would imply that you could potentially use one in each hand.
But even as a paired weapon, vibro-axes would not be as deadly as the heavy blaster with auto-fire.