I recently got an open boxed denon 2801. Should i upgrade to 2802 or 3802? What would be my benefits? Is dolby prologic II much better? I would still be using 5.1. Is dts-es a factor then? The 2802/3802 has component switching, but can they pass a hd signal? Would they sound any better? Sorry about all these dumb questions. I'm new to the game.