I voted for grimmjow as we get to see his character actually flesh out and know who he was, while we almost get nothing from ulquira except what we get from face value he almost seems tsundere when he almost seems to take pity on input and this just means to me that he has no actual individual he's basically the cool guy who can do cool things and is basically a jumble of cliches, thank god he died and was useful in activating ichigos hollow.