I just installed the card tonight. Went in without a hitch. Since I'm running Mandriva 2006 x86-64, the card was automatically detected at boot, and the CMIPCI driver is being used to drive it. I'm pretty sure that this is a generic driver for other CMedia chips, but it *does* give me stereo audio right off the boot. Once I have a bit more time, I'll upgrade my version of ALSA, and see what happens when I use the 8768 driver (for the previous X-Mystique) - in an attempt to get multichannel sound.
For kicks, I rebooted to Windows 2000 (which I use only for Lightscribe...that is until k3b supports it in the next few months), and installed the drivers for the X-Plosion. The control panels are nice, with graphics to help understand your config setup. I haven't tried using it to stream digital output to my Denon receiver yet (via ONE optical cable...), but I will in the next week or so...which means I'll have to install Half-Life 2 or somthing to the Win2K boot.
Anyway, the very basics of the card function "out of the box" under both Windows and linux. The only gripe I have with the card is that it lacks a header to attach to PC case front mic and headphone outputs. In my case, this is very minor, since I can attach my headphones to the receiver - but for some, this will be a dealbreaker.
-Adrian