What's the difference between Samsung's Home Cinema HTZ220R and HTZ320R?

Apart from price. One must be better or a newer model, anyone know? I can't find a site that compares them (including Samsung's own site)What's the difference between Samsung's Home Cinema HTZ220R and HTZ320R?HTZ320R - More power (RMS), can rip cds to MP3, better file support for USB playback - one site says it plays BluRay but the manual doesn't specify that it does