This is guesswork based on a previous experience of similar stuff, but I think the Orbital will, mostly likely, be more wind resistant - a quick blow test suggests it's pretty much windproof - but possibily not quite as breathable or as fast wicking, but I'd still expect it to be significantly better than than a membrane fabric. The ME fabric's smoother face may also be more abrasion resistant, but it's hard to know.
That's what I'd expect, but it's not always the way you think it will be. We're actually getting an Orbital in for review, so I should have a better idea before too long.