The Apple A1003 AC adapter, (which I believe does NOT come included with an iPod) is a good, efficient charger cum USB connector. It is an Apple manufactured item, so as long as the connector fits, it's pretty much guaranteed to work. I have used it with an old school iPod classic 3G, Classic 5G and a nano 3G and it has worked on all three models. Here is how the charger is built. The standard iPod charging connector has two cables emnating from it: one is the USB connector end, and one is a firewire end that connects into the charger head. I understand the design is so to provide independent charger and USB functions, but the cables tend to get a bit messy. They are pretty long, and if you're pulling the charger head out, it is hard to control the USB end at the same time, since it is not directly connected to the charger head. The nice thing about having separate USB and charging connectors is that you don't need to have the USB end inserted into the computer to charge. This saves the iPod hard drive from unnecessarily being read. So unlike with the USB cable that the iPod comes with, you do not need to eject the iPod everytime, simply not plugging in the USB end works. Sound Quality N/A. This is an adapter. Battery Life N/A. This is an adapter. Design Cables tend to get a little messy.