I'm going to be building a vista machine in a few weeks and I would like to know opinions on whether or not to purchase a soundcard (X-Fi) for the new machine due to vista's way of handling sound.  What are the advantages and/or disadvantages??
 
Thanks

No... use onboard. If you arent satisfied then and only then decide to get a soundcard.

Yep, you won't hear a difference anyway. Use the money for better speakers, which will let you hear a difference.

Given the fact that additional Sound cards would cost ~90$, the money could easily be invested elsewhere for greater benefits unless you are an audiophile and would really notice a subtle difference. Depending on you gaming build, you have to keep in mind that if you go SLI with dual-slot video cards, you might end-up with only a single free PCI slot, sometimes none.

Vista has serious issues with X-fi soundcards, onboard is good anyway. As Zenthar and dagger have said use the extra money to get better speakers/CPU/GPU.