I had to register just to comment on the Proton AS-2631. I recently purchased this processor on EBAY. I think the seller was they trying to 'clean out' there inventory of these units becase they had 25+ units for sale via dutch auction. This seller normally sells them for $850 on their web site (still does), but they were getting rid of them for $275. Although it was a nice sounding unit, I had nothing but trouble with the units led display. I actually went thru 3 units and each one had some display related problem. Fortunatly the seller worked with me and tried to supply me a properly functioning unit. After the 3rd unit I gave up and got my money back. The seller mentioned they had other buyers with similar problems. These units were 'new', not refurbs/returns. As far as features, it really only has 5.1 DD and DTS. There are no simulated surround modes and no 5.1 analog input for SACD or DVD-A.