Before every one goes bashing the new material, the old material is NOT made anymore, thats what prompted the switch. Moreover, for older Cadets you might remember if you had friends that smoked or burn polished it was quite flammable compared to normal clothing and our current stuff.
The creases, once they're in should stay in unless you really toss your pants around; a hot iron will effectivly melt the creases in to the fabric.
I have had uniforms made of both, and worn battle dress. I hated the ladder, and of the two fabrics prefer the new; looks better, doesnt wrinkle as easily, doesn't fade as easily, irons well (the old stuff got shiny as well, hate to tell ya
), doesn't hold smells as distinctly, is darker (hides dirt, see: CSTC), and is considerably more durable (harder to brun, rip, and impossible to pull)
Chimo