Well I've had it for about a week now. I did a reformat on my system this weekend to make sure all was good in the world, so I can start to post some comments on it now.
First off. It just sounds plain better than the old Audigy2 ZS that was in my system prior. The upper end is much more clear, and articulated.
Directional location of sounds is much better as well (running in 5.1 surround)
The biggest difference is having proper bass back without having to mess with settings too much (+15 db bass option under gaming console).
I may be missing something in the settings, but there doesn't seem to be a way to optimize your speakers for your specific setup (distances, and balance are missing), so that seems to be a glaring omission (there is one for THX, but that's it). I'll look on the CD to see if I just goofed up here.
I didn't have any problems with the cards setup @ all, but it should probably be noted that some people are having problems with them:
http://forums.creative.com/creativelabs/board/message?board.id=soundblaster&message.id=26289
It seems this problem may be more bios (mobo) related than soundcard.
I've only tried a few games so far: Thief3, FEAR, UT2K4,and BF1942. BF42 has a tendency to crash on occasion with a sound loop, but I am inlined to blame BF42 rather than anything else. In all fairness it seemed more prevailent when playing the Battlegroup42 mod over Desert Combat, or just plain 'ol BF42. The locations of sounds was great though in all games.
I am not using the Crystalizer function. It doesn't impress me that much (or for that matter...at all) & seems more like a bell than anything. Music (mp3's & cd's) sound much better on this card too. I haven't attacked any other features on the card yet, so this is about all I comment on for right now. All I can say is that I'm pretty happy with my purchase so far.