Which cell phones is better - the Sony Ericsson Walkman W760a or the Motorola Rokr E8.?

I was wondering which of these two cell phones has the better music player, because I was going to use them primarily for music listening. It would be good to know which of these has a better battery life. And last of all, overall user experience. How easy it is to use it, are you comfortable with it, and the interface. Thanks in advance. If you need additional details about my needs, please ask.