[iLikeJarJar]

Hi, I was wondering if anyone more experience could shine in on my question. Would it be worth having say the FiiO E10 and ASUS Xonar Essence STX sound card? Besides the ASUS's gaming benefits from the OS driver, would a setup of both the E10 and ASUS improve quality? Thanks!

 

[mikeaj]

E10 is USB input only, so you'd be using one or the other.  Unless maybe you're driving some multi balanced armature IEMs with crossovers or something else with low but highly variable impedance over frequency, STX is probably going to be better anyway.
 
If you want Dolby Headphone or some other processing features, some of the lower-end Asus (and other) lineup have that functionality as well.  I don't think it's worth spending any more on non-headphones hardware at the point you're at, if you want sound quality improvements.