Asus sound card and a DAC are essentially the same thing. You might know that, just clarifying.
You will get good sound sound from the Asus Sound Card.
I haven't played Far Cry 3, but it could be the game causing the issue. I know with Bioshock Infinite, sounds were just 2 channel.
Sorround Sound was useless in that game.
Yeah, at this point I'm just mulling over the pros and cons of each. Leaning towards the DAC. The only real con I can come up with is that it'll take up a USB port, which are in short supply for me. I have too much stuff hooked up to my computer.