Unfortunately, the only Asus soundcard that is close to the Creative X-Fi Titanium HD is the Asus Xonar Essence STX. And when I say close to, I mean near the same level, most definitely not superior at all, especially with its stock dry and harsh sound.
You might be thinking of regular X-Fi Titanium cards, and with that I can agree, but the Titanium HD is a different card altogether.
Apparently, you have little to no experience with Creative cards (Audigy and X-Fi series), or you would know how improved positional cues are. I'm not talking about surround virtualization techs at all, mind you, as both Asus and Creative solutions are awful in that regard, but it's an acquired taste.
For music playback, both the Xonar Essence STX and the Titanium HD are exactly on the same level, with the Essence STX being drier sounding and the Titanium HD being warmer sounding. It's not a personal opinion, it's widespread reviewing.
In terms of gaming, the Essence STX has as much capabilities as a $1 onboard audio chip, so it is laughable that it is compared to the Titanium HD. Even the lower quality X-Fi Titanium slaughters the Essence STX, nevermind the version with a newer DAC, higher quality opamps, and the same full gaming audio feature set support. For gaming, the Essence STX (and all Asus cards for that matter) is a joke.
EDIT: The O2 is indeed an amp worth getting, but adding it to an Essence STX would even make its sound less pleasant, as it's on the bright side of neutral, while adding it to a Titanium HD wouldn't hurt the signature at all. But if you followed the OP's posts, you would know that part of the chain is something to be obtained further down the line.
EDIT2: I forgot to mention that Asus soundcards are incapable of passing through sound processing through line-out, while that's available on the Titanium HD if desired.
Last edited by tribaljet; Jun 18, 2012 at 02:07 PM.