Yes... and you don't think the muxing changes based on the sound card (and drives) you have installed for said sound card? Heck this can easily be seen based on how sound cards/integrated deal with microphone input. Even if they have good components, using the same mic you can sound like ass on one and great on another. It may just be the software, it may be the hardware, but the overall experience does change.
Mixing is one thing. These days all the mixing is done in software so there's little to nothing to be gained from one card to the other. However, as microphone input goes, all the money is in the preamp in question. And of course, a cheaper soundcard will have a pretty poor mic preamp, that's to be expected.
No, no way does CMSS-3D simply add 'pop' by doing virtualization. You must not have used it if that's all you think it does. Playing a game like BF3 with CMSS-3D is a totally different experience then playing it with a simple stereo output or even Dolbys version (which does suck). I know, I've tested both of them as is stated in this thread.
Perhaps CMSS-3D's simulation actually works ok for BF3. But historically, all these "surround expanders", "simulators", etc, do more harm than good. In other words, if you do have a game it works ok with, it's going to sound horrible in the next ten.
Sound simply isn't raw data that is fed to whatever device that is hooked up to your computer unless it's passed through like a DD stream from DVD or Blu-ray.
Actually, these days, I'm afraid it's pretty much what it is, with software mixing having become the norm. Even the volume changes are done by Windows/driver, not the soundcard. There's an exception about mixing an input with your output (i.e. mixing your line input with your main out), but that's a corner case.
A more expensive soundcard will get you, most to least important (IMO):
- Better output DACs.
- Better drivers (unless you're Asus har har).
- DTS Connect / Dolby Digital Live digital surround output.
- Possibly a dedicated headphone output with amp.
- Better input DACs and mic preamps.