The surround simulation from the newer external Creatives (E3/E5) isn't as good as with the internal cards, they made one compromise too many, probably to keep the price down.
Also, it's no good making blanket statements that Creative is better than Asus when it comes to surround as a great deal depends on the ears hearing it and what may work best for one person may be different for another.
It's true that Dolby Headphone has atrocious reverb but only in mode 3 and gaming mode generally uses mode 2, which is very much subdued compared to mode 3.