Those Xitel boxes look interesting, and they are cheap too. They seem to target people who want to play music out of their system with high quality, and little work to install. Good for its market. I was, however, looking for a lot more than just a fancy DAC.
I bought the Audigy Notebook because I wanted to not just move up in sound quality, but to get the 64 channels of DirectSound3D hardware acceleration and EAX 1,2,3,4 hardware support. I'm mainly a gamer, but I also like to listen to music as much as the next guy, so I wanted something for games first. And, Creative just indisputably owns the gaming audio card market (sadly). I paid for it, obviously, at $130. But to me it was worth it to get the better positional audio, performance, and quality.
BTW, I've been playing Chronicles of Riddick on my notebook and I'm not having any audio quality problems with this game, even in full 3D audio and EAX mode in the game. Positional audio on headphones is very good. I can tell spatially where something is. Quite nice. Lots better than my Realtek built-in crap.
So, so far Halo and SW:JK:JA are games giving me audio probs.