If you're really worried about CPU utilization, then yeah, it's worth it. But if you're not so worried about a 5% drop in frame rates, then you can save $70 and get
this card (AV-710).
Its multichannel is not the greatest, but it has one very high quality DAC in the 7/8 jack. You can reassign this to be used for stereo mode in a 2.1 speaker set and not use the lesser DACs. For a 2.1 speaker set (or if you're using it in digital mode like I am) It's an incredible value. Excellent card for music, but it doesn't do hardware processing for games so you'll lose a couple FPS... but if you save $70 from it, that's $70 that could be spent elsewhere (more ram if you have 512mb, towards a better videocard eventually, better CPU etc.) and you'll easily make up the couple FPS drop from the soundcard.