Here is the bottom line.
If you use onboard sound (like me) you will probably notice quite a bit of difference in performance between onboard and an Audigy 2 or above.
If you have an Audigy 2 you will probably not notice any increase in gaming performance, but there will be more sounds and perhaps better quality sound.
If you use speakers (surround sound) and have an Audigy 2, the difference will be kind of clear, but not as good as with a headset/headphones.
I heard that the X-Fi really shines when it comes to gaming with headphones.
I don't know if there will be a huge positive difference with a 2.1 speaker set.
As I said above X-Ram is kinda useless now, but the Fatal1ty is a great deal if you wanted the additional accessories.
Hmmm I don't know which one to keep! $60 or $120!