KitGuru tried the NZXT Manta Chassis
A quote from the article:
NZXT has launched a Mini-ITX case called Manta that breaks the rules, defies expectations and looks pretty darned cute into the bargain. Take a look at our video and photos and you will see that all the panels on the Manta are curved. This is a novel styling trick that looks good, gives extra space inside the case for cable management and also helps NZXT to conceal the intake and exhaust vents on the top and front of the case.NZXT Manta Chassis Review @ KitGuru