OP, if you do go for this make sure you have clean power. At least for the Fulla (one tier down) some units had issues with whine and hiss, as a result of being USB powered instead of wall powered. For the most part though they make good stuff.
USB is garbage for audio ime, for a variety of reasons. But yeah... USB power is the worst sin next to data hash noise popping down the ground and up thru ya outputs. And even when it works, it doesn't sound as good as proper spdif. Worth mentioning, you can now get their Unison USB in their new Modius DAC. Until now, you had to spend about 8 hundo chunks to get it and there was nothing better. Really makes other USB audio stuff look lame. It's much closer to being immune to the follies of USB audio. Schiit hates USB. They've been at war with it from the beginning.
It's funny. Asus likes to push thier whole sound suite. Really it's not bad. Just kinda average. But you know what's NOT average? Their USB. Probably the worst possible USB bus to feed a DAC from. I mean it. You will hear your computer's thoughts through your speakers. All of their AMD boards, anyway...
I gave up on mobo audio a long time ago. Modi Multibit and Vali 2 for me. You wanna drive high-impedance headphones? Gotta have a dedicated amp. Generally. Why buy enthusiast cans just to plug them into a mobo, right?
They are running out of excuses, though. See, I've got an LG G8 ThinQ that drives 300ohm HD6xx's pretty close to "WAYYY TOO F***NG LOUD" territory, sounds good, has DSP correction, EQ, and even different DAC filtering modes! Adaptive gain for line-level, low impedance, and high impedance. It ramps up/down for whatever you plug-in. Here's the kicker: this is a not a revolutionary development by LG. It's all on one chip: an ESS ES9218P. On this thing, you get a DAC (clock built-in too, this does matter when you consider that even decent DAPs tend to use the cheapest clocks they can get that work,) variable gain amp, and the post processing magicks. You can pretty much drop it in for a full audio solution and it sounds damned good... like actually pretty resolving, a little slammin... with nice, even timbre. I'm picky and I like it. Worth mentioning, I HATE Sabre sound as much as I hate AKM's velvet warmpoo. This still impressed me.
Not sure how it would affect BOM, but a chip like this is probably the simplest way to get audio on a board, period and have a consistently good, versatile sound. Simpler than what's on your mobo that's failing to keep up.
For many many years, DACs and opamps didn't really improve much. Times have changed though, and so much can be had on a couple of chips, or now even all on one! Both ESS and AKM have done changed the game these past 7 odd years. I get that it's not a top consideration for mobo makers, but it doesn't require a revolutionary effort anymore. Baseline good audio is trivial and mobo makers are lagging. Some of these combo chips out there are so good you can pretty much drop them in and call it a day, and they will DESTROY any of the current mobo audio implementations fairly easily. Again, they are really running out of excuses, especially ones like Asus, who make audio a selling point. They need to look at what is happening with mobile audio and realize they can have that for pretty cheap and actually free up board space and streamline their process. Software stuff is firmware on those types of chips... just hook in and get fancy features. It should be a no-brainer. They just aren't thinking about it at all.
Of course, they'll probably never compare to discreet boxes. A few people mentioned Schiit. What I really like about Schiit is that they're actually engineering their budget stuff. For ~$200 you can have a stack with actual discreet circuits. Modi 3/Magni 3 is hard to beat. Or Asgard. Not just chip-in-a-box, or by-the-datasheet op-amp designs. You'll never get that inside your PC case, and the sound will reflect that.