I just got my
Z80 and I think the sound is not very good at all...it sounds as if it is playing in reverb and has a hollow sound and the bass is definitely lacking. This doesn't even come close to my iRiver H120. It had stock/custom EQ, WOW, TrueBass, and more. I put an iPod battery in it and it was good for 20 hrs. The only reason I'm not using it is that the HD died after 4 years.
Everybody says how awesome the Zune sound is....as compared to what? Very disappointed.