I just got mine, and all I can say is: WOW! Haven't tried it with my D2 Boa yet, but the night is young.

The one thing I noticed is that the interface isn't as smooth as the iPod. It tries to fade the music in and out when you pause, but fails at times to do it elegantly. It tries to switch tracks silently but sometimes there's a click. Nothing big but if you're a perfectionist it will drive you crazy.