i voted for the halo, only because in this instance, i like the setting more. i typically love/prefer antique or estate rings, but the halo one you're showing is gorgeous.
it looks like one of ericad's rings, too. is that a cushion cut? it's exquisite.
i honestly doubt that the halo setting "will go out of style." i think because it's such a beautiful style/setting that it's something that will always be "in style."
i mean, how could a ring like that be a trend? kwim?