Go for the Aveo.. I own a Chevrolet Nabira (in malaysia: In Singapore, it's an Opel Zefira). THe build quality from Chevrolet is better as it's got the 'German' feel to it due to the Opel association. (the door slams with a solid 'thuk' instead of a clanging loose metal sound commonin most Korean cars).
Have sat on Aveos: The Aveo has great suspension systems, going over humps feel like nothin..
my 2 cents