Totally different things!!
P.S the pod doesnt charge from usb at all only firewire or the ac adaptor included (yes there is one!) usb (2) is just for sync of data
i have a sony MZ-N710 since december 2003 and had a N70 B4 that..i recently got a 3rd gen ipod with 40Gb..i havnt looked at the MD unit for weeks..still love it but wont use it no point..i will always want to play something i dont have with me..cant happen with the pod..(btw majority of music is @ Mp3 192Kbs altough cos there is soo much capacity remaning i am encoding at 320 Kbs now) and with pod i can transfer anything from my pooter or ant pooter in most formats (except wma who cares!) and transfer back to my or any pc..with 9.4 days of continuos music the pod wins hands down and its half full!
its also a fully featured 40 gig removable portable hard drive (if u have a laptop its a godsend) and if u drive alot then an itrip can keep u with tunes till the cows come home!!
but it does have a kack battery life both short term and the overall life (forever i dont think!) although it can be replaced ..its to expensive to take everywhere and it too expensive to buy..plus the apple headphones are gay! (no offence!!)
if u have the money have both! if u dont have the MD and save!
its about what u need they ARE totally different machines
