Hi, Brad. When I moved from my Yamaha RX-V992 to a newer Pioneer VSX-1015 in 2005, I was extremely pleased. The VSX-1015 had better processing, and even more important to me, it had an auto set-up routine that adjusted equalizer settings that really made my system sound better. So, I'm thinking that a move to a newer receiver (or pre/pro) with auto set-up might give you the same improvements.
Are there any other desires besides DD and DTS? Do you want to add HDMI connectivity? Newer lossless codecs?