The sound quality is also better on the Zen. The Zen has an integrated headphone amp that will drive a wide range of headphones...even the larger studio cans can be run off of them. The headphone amp on the iPod is junk, as it will only run earbuds or only the smallest headphones. If you want some bad ass headphones check out the
Sennheiser PMX200s. I have the older model of those headphones and theyre great. They have a nice 18 to 21000Hz range...so theyll get the lowest lows and the highest highs.