Ok, I've had an iPod since the beginning of my mp3 days but I am now switching over to the Creative Zen after my iPod died. I have had some issues with the iPod and I just got sick of sending it back to get fixed. One teenie little problem. My entire library is in AAC 128kbps. What I need to know is if I encode it all into MP3 128kbps using the iPod encoder will I notice much of a difference in sound quality?