I love the Fatal1ty X-FI, especially for gaming, but I do a lot of music with it, and I like that it is easy to switch modes.
I run XP, and I updated my drivers about 2 months ago after running the card for 2 years now.
I got the Fatal1ty version, because it comes with X-RAM which gives it a performance boost for gaming - but I haven't been able to confirm this.
The Fatal1ty Champion version (the one I got) comes with the front panel, which is great but I wish it amplified the output so I would really crank up the headphones!!
Now read somewhere that there is going to be a new Fatal1ty X-FI for PCI-E later this year, and it will get a new front panel with amplified sound, so I am looking forward to up-grading to that one.
I did install a Auzentech X-Fi card in a friends machine with Vista, and it worked well, but I thought it was missing some of the little software features of the Creative X-FI, and I thought the default bass responce was a little better for the Fatal1ty X-FI then the Auzentech.