The drivers aren't terrible, I can't run bioshock with EAX on, but I can run it with just regualr 7.1. Crysis runs fantastically, Oblivion runs much better (not perfect, tho there are many reasons for a C2D every ****ing half hour) since the new drivers came out (october I think. They aren't very good at getting drivers out, but at least the card is pretty much useable.
From my experience, the "sound card" that came with the S2E was slightly better than regular on board sound ( possibly due to having its own in built processor?) but the D2X is excellent. It almost makes spending £300 on headphones worth it (yes I did). Even on the cheap speakers I've got (RMS about 70 watts total) it sounds great.
I second the comments about creatives...I've got friends who have complained at the once a millenia driver releases.