Maybe I'm showing my age on the fabric issue, having not been around to soldier in anything before BDUs. As for the issues TR mentions, I'd think durability would be one of the vital attributes, fading far less so, but still a concern (not for appearance in formation, mind you, but for the maintenance of camouflage), and permanent-press not a concern at all. In the ideal world, that is, where the Army selected uniforms, equipment, and weaponry based on what worked best for the tactical soldier, not the PAC clerk, staff weenie, or maternity-wearer.
As for fabric, then, a question: what would be superior? There's a lot of categories that need be considered. Durable, breathable, cool (I don't see us fighting many militants in Sweden any time soon
), quick-drying, fade-proof, skin-feel/nap? You can have the softest fabric around, but if it rips on a wait-a-minute vine, it's useless; likewise, the most durable fabric is useless if it chafes/irritates.