Hey nice review. I have the MX 580's. They sound really good for earbuds. nice and open sound. The only other headphones I own are Bose - Better Sound Through Marketing™ Around Ears, which are ok I SPOSE. I used to have Shure E2C's (lost them) and the MX580's sound better to me than the E2C's. Everything has advantages and drawbacks, but for $25, the MX580's can't be beat by anything in the price category, for shure. ha!
The MX580's sound much better when amped through pc speakers, much more full sound, deeper bass, etc.
But, good thing Senn has a 2 year warranty b/c i have a slight buzzing sound when there is deep bass in a song in my left earbud. No complaints though b/c their warranty covers ANY defects in sound for 2 years! I'm definately a fan of this company now.
I never auditioned Yuin's, but based on your review, I'm not missing much for the sound quality with the MUCH less costly MX580's. German Engineering vs Chinese Stuff. Choice is CLEAR.