I used dedicated sound cards for almost 20 years, from the original sound blaster to the audigy 2 zs platinum and every SB inbetween. But now, my last 2 systems I've used onboard audio. The onboard sound has come a long way since it was first integrated into the motherboard. Unless you're doing some heavy audio stuff (composing music) or have some killer speaker setup, you won't notice any difference with the onboard over the dedicated card.
But if you already have the audigy card installed and don't need the pci slot for anything else, then go for it. Only issue I'd see is Creative's drivers can sometimes be finicky in certain situations. And Creative is unlikely to help these days after they shut down their forum.