I had a Creative Labs Audigy 2 and a Platinum on a different machine, they worked fine untill I started recording longer takes (eg a 5 minute rhythm take) and using more 3rd party plug-ins. The Audigy 2 also suffered when I used sample based VSTi's such as DFHS. EastWest Symphonic Orchestra and Giga Studio would not run at all untill I upgraded to a specialist card and Halion showed the usual latency issues plus cracks and pops.
At the end of the day it depends on what kind of a load you intend to put the card under. CL cards work fine for editing small files and sequencing them in entry level sequencers, and that is not a slight on Creative Labs or users of their cards. Cubase SX3 for example has some very power hungry plug-ins that require a card that can handle zero latency. No point splashing out big money if you arent planning on using these types of plugs or sequencers but if you do then you will just end up upgrading. Creative labs cards are more suited (and very well suited) to playing mp3's, dvd's and surround sound applications associated with pc games. Just my advice based on looking at a high spec system (from expensive experience!).