I recently purchased the B&W 600 series (602 front,600 center,601 rear) along with a Denon 3802. My CD player, VCR player are quite old (5-7 years) and my DVD player is about 2 years old. Would it be worth upgrading these components? I know that there are DVD/CD combos, and now DVD/CD/SACD/DVD-A combos. While convenient, would separate components be better - that is, not only in sound/video quality but price/performance? Or are there combos that match separates in these categories? Thanks.