I'm quite a mobile person, working with some PCs and laptops. The problem is, those onboard sound cards quality really irritate me. I really like to hear any though on Senn PC155 USB. How good Senn' DAC on PC155 USB compared to, let say, SB Live!, Onboard AC97 or Portable CD Player ? Or maybe you have other suggestion ?

note: mostly I will hear from CD (DAE mode) or APEs, rarely mp3.

Thanks.