Such is life guys. The specs and tests don't lie, Fram XG2 crushes the wix in every metric. Lots of discussion on "the other ram forum" and bitog about these filters. I'm just reporting the information I've picked up.
Normally I wouldn't care, I'd just run any filter, but the hemi is particularly sensitive with it's needle bearing failures, and its crucial that any deposits or carbon or varnish be kept out of those bearings at all costs. I'd never run anything with the poor efficiency rating of the wix on a hemi. Other cars its probably totally ok.
Edit: the hemi is also particularly a dirty engine. Double trouble when added to the lifter failures.