Just my two cents . . . I'd opt for the X-Fi Xtreme Gamer Fatal1ty Pro (or whatever their current equivalent is). Although there are only a few games that support the use of the onboard 64MB X-RAM, the audio processor on these cards can handle a ton more channels at a higher quality than the lower cards can, and take even more work of the CPU for gaming. I've had Doom3 and Quake4 running before, both with EAX 5.0 enabled, and I think the highest number of sounds I recorded that were loaded up was somewhere near 157 (according to the Doom3 engine) at 44.1 kHz - even though the card is rated at a max of 124 - with no crackling, popping, snapping, screeching or other audio noise. The audio processor also runs true 24-bit in both playback and recording whereas most of Creative's lower card models only support 24-bit at certain frequencies.
I can say from experience, as I owned an Xtreme Gamer before I returned it for the XG Fatal1ty Pro - there was a night and day difference between the cards. The F-Pro was able to play more sounds, sounded better, and hell, even the 3D sound through some cheap-o gaming headphones was superb (and it has made a ton of difference gaming in D3 or Q4!).
Downfall, though, the Xtreme Gamer Fala1ty Pro is about $150 - nearly twice as much as the Xtreme Gamer or Xtreme Music. Also, the F-Pro is even more of a BUS hog than the lower cards are, and if you're running nVidia hardware (even a NSB or SSB chipset), there's always a possiblity you'll run into playback issues (even with the lower cards, but, the higher the BUS dependancy, the more frequent the problem) - if you can manually set your PCI BUS freq, though, you might be able to circumvent that problem.
Oh, and the F-Pro can also be connected to your front panel connectors (I don't remember the XG having the F/P connector), but it requires a little work, unless you buy the $80 Front Panel I/O drive.
Just to mention - as I thought this was a bit odd when I first saw it - but the XG F-Pro is the first audio processor I have ever seen that employs the use of a heat sink. Crazy.
Hoep this helps, if you've got some more questions about the card, just ask man
Edit: wanted to mention - the drivers can still be a little buggy at times, especially for Vista users. I had to run with the drivers on the installation CD for the longest time, as the update driver provided by Creative was giving me loud screeching with CMSS-3D and EAX 5.0 - but that went away once I had the ASUS mobo. Just to make sure, I lowered the PCI BUS latency in the BIOS to 32 from the native 64, and assigned the X-Fi's PCI slot an IRQ number that wasn't being used - no more problems at all, and the update driver worked perfectly fine.
Driver isues have also been buggy for their co-branded cards, from what I hear, and no one is sure when any of those are going to be released or 100% non-issue. Creative also supposedly has a PCI-e x16 card in the works to allieviate BUS hogging on the slower PCI slots, but I can't really see any gamer or performance enthusiast willing to sacrifice an x16 slot for an audio card.
The X-Fi F-Pro does support 24-bit lossless audio ripping, although it takes a lot of time (45+ minutes for a 1hr CD on my rig).
Also, try to not go to Creative's site, as they update all the time, and re-write a ton of their crap as they make mistakes and correct them. I usually use the Soundblaster site,
http://www.soundblaster.com/, although it's not updated as frequently, the info presented tends to be more correct than what's found on Creative's main site.
