I had to abandon my internal Sound Blaster card when I got a motherboard that didn't have any extra PCIe slots (I run 2 GPUs). The X3 fills the role nicely, and gives better sound quality to boot. Definitely get the X3 if you can find one, rather than the X4. It has a superior Asahi Kasei AKM AK4458VN DAC processor, while the X4 uses Cirrus Logic (due to chip shortage).
Software is fine. It just works. Set and forget.