The "Xtreme Audio" isn't actually an X-Fi. It's just old Creative tech rebranded (whats new there though
)
As for the X-Fi range? Very average in my opinion. Certainly nothing ground breaking like the advertising makes out. I'm not saying it won't be better than some on-board sound solutions, but every time Creative being out a new card range their advertising makes it sound like they have discovered a way to insert a thousand Chuck Norris super dwarfs in your ears, each with a different instrument to play the exact sound you want.
Then you run the risk of Creative removing features that
you have paid for at a later date through driver "updates". Google this if you have not come across it before.
Oh, and moving to Creative because you're having driver issues with your current card is like choosing if you want your best mate or a stranger to kick in you in the balls. It doesn't matter who you chose, you're still being kicked in the balls
Creative to this day still have really bad drivers.