Wisetooth has a familiar look and shape. The hollow blade motif is a familiar one in fantasy, so it ends up looking slightly generic. Having said that I like the thickness and spiking on the end that gives a sense that the blade, while lightened due to its hollow nature, would still have a great deal of heft and momentum.
Nautilus looks a lot like the baby brother of the Soul Edge. I'm waiting for the jewel in the cross guard to swivel around and glare at me before the entire sword opens up and reveals what looks like blades to actually be the teeth of a bottomless maw.
Honestly, Wisetooth seems to be the least cumbersome, and the Nautilus is for those with unbreakable wrists. However, it's not about practicality, it's about maintaining fear and looking awesome doing so! The coolest part though would be the campaign history between them (assuming they got their names due to heroic or infamous acts), I wonder at the possibilities.