I moved from the Denon 3805 to the 4311 using my M80's based setup. I have a big room, and I liked to have the M80's properly powered, so I ended up adding an XPA-3 to add more juice, not that it really needed it, but the XPA-3 added a little bit extra and I feel that improved the sound of my setup.
I believe that the difference in power between the 3805 and the 4311 to be not that big. I could detect that the 4311 without the outboard amps was more powerful than the 3805, but the difference is not pronounced.
The biggest improvement came from Audyssey MultEQ XT32. Once I completed the Audyssey calibration and when I run the system in Audyssey DSX mode, the sound suddenly opens up and the system sounds incredible. I have not demoed many calibrated systems, but judging by various demo rooms and cinemas ...etc, my system sounds better that everything I heard before. My room is untreated, large, and the shape of the room is awkward.
I would say go with the upgrade, just make sure that the new receiver has Audyssey MultEQ XT32, calibrate and enjoy. I am re-watching movies and re-listening to music because I am hearing details that I have not heard before, it is that good.
I was listening to Pink Floyd's The Wall from the new discovery set a couple of days ago. This is one of my favourit albums, and it is the first time I play the re-engineered CD on the new system. I played it on my NAD CD player with the 4311 in Audyssey DSX Dolby PLII mode. It was incredible and I am very pleased with the sound. It does not get much better than this in this hobby.
Sorry if I seem to excited, because I am, but go for it. You do not know what you are missing.
