I'm new to all this HD-DVD business but I am wondering am I better off getting the Xbox 360 add-on or a standalone player? I know the add-on upscales normal DVDs too as does the standalone player, I'm swaying more towards the add-on as it's a cheap alternative which does the job whilst upscales aswell. Is their any difference in picture quality etc? I'm viewing on a 37" TV from about 7-8 feet away. Thanks.