Not really, that card won't do much gaming wise. I used to have one like that, the chip is crap and run EAX emulated, albeit a little better than realtek. As for sound quality if you have an realtek HD then it will not be much different. If you have an realtek AC97, then that card might improve the soung a little.
I recently upgraded from a Realtek 8 Channels ALC888 integrated Audio controller to the Audigy SE.
(Like you I was wondering if it was worth the money)
A slight increase in sound quality. Also I like the Creative Audio settings. it's a bit like my Iriver MP3 Player "3D" mode, although the Iriver still deliver the best sound quality of any hardware I have owned.
I also got a tremendous increase in Microphone input quality.
It's was one of the reason pushing the upgrade. I got crappy result with the Realtek microphone, and the micro integrated to my Microsoft webcam was not that great either. I was used to power on the Thinkpad for skype calls as it got a very decent micro.
Now recording quality is great, even better than on the Thinkpad.
If u want better quality you have to pocket much more money for the next good offering.
I understand that the first cards in the X-fi line (xtreme audio and xtreme player) are almost the same hardware wise as the audigy SE, with an heavier software package, so It don't seem a good deal. So if you want better you should look at the mid range X-Fi.
You may also want to read the user's reviews on Newegg, that here that I found the more user's opinions on the Audigy and on the others cards.
You should see a slight improvement all round (provided its WinXP dont think Vista likes these yet)... although you will want some good speakers to hear it
Sound quality will also depend on which AC97 chip is used. Some have better sound quality than the old audigies.
The audigy SE also does not have hardware DSP. As such dont expect any framerate gains as its all going to go onto the CPU anyway. For a cheap soundcard I would recommend a audigy 2 ZS it has hardware DSP and they are real cheap these days.