Yes, that's the trick of this card is that is uses an Alchemy like wrapper to more or less trick a game into thinking you have full EAX support in Vista, which it that processes in software. Its probably not quite as good, but good enough to avoid dealing with Creative. Otherwise, it just offers hardware EAX 1.0 & 2.0 like every other non-Creative card (save the Auzentech X-fi)
As far as whether its better than the Razer AC-1, I've had problems with Razer's drivers and whatnot, though the Razer can do DTS-Interactive while the DX can only do Dolby Digital Live (the D2X can do DTS, but its $100+ more). Its debatable I suppose, though reviews seem to indicate Asus comes out on top of just about everything for gaming.