Hey Dan,
That is ain interesting comparison you have there between those two systems. Hard for me to speak from experience because I went from a HTIB Yamaha to my Sony 3300ES AVR..(go ahead bash me)... I didn't see the need for the hdmi 1.3 whistles either so I opted for the 3300ES and saved a bunch of money since it accepts PCM. Because I went up in speakers and avr the difference I heard was astounding. Taking a look at the codecs of lossless to lossy there is a difference in bandwith of the signal and ofcourse its compression. DD is usually around 648Kbps DTS is 1.5Mbps then the Lossless stuff gets around True HD = 4.0 Mbps Dts HD = 5/6 Mbps and PCM is almost at 7.0 Mbps.. Those differences are quite large.. but listening between the tracks on my current system the biggest difference is from DD to PCM. Going from DTS to DTS-HD yields the smallest difference in sound.
When I say difference in sound I mean the overall experience of the movie with sound dynamics and use of the surrounds. So with the DD lossy signal the dynamics of sound say in gunshots and high action scenes is not very large, and the dynamic of PCM gives you pure ucompressed audio as it was recorded so to speak with full dynamic and use of the surrounds.
Thinking about your comparison it could be argued that the higher end AVR with more power might be able to produce that dynamic virtually. But some of the added detail in the sound track for the movie would not be present, so you would probably notice a difference in that aspect.
I have the ACDC Live at Dottington Blu Ray and have played both the PCM and DD tracks. Set to the same volume level the DD track seems very weak and the detail of the sound doesn't sound as realistic as the PCM track. No increasing the volume of the DD track I could achieve the same level of sound but still the detail just isn't there. Again this is using the same AVR to do the comparison which has no bearing on what you are trying to accomplish, but still I am able to verify audible difference between the PCM track and DD track on a blu ray..
I hope that helps out in some way... Maybe another Denon to look at would be the 2308ci.... I am not sure what the WPC is rated for but I know it is at least 100WPC..
I hope some of this helped..
Rockarruda