i can speak somewhat intelligently (but can't spell!) on this topic as i previously owner the Denon 5805 and currently own the 4306.
overall impressions:
the 5805 is the real deal, 10 assignable amps alone make this one of the best receivers (probably the best) out there. the 4306 does not even approach this amount of flexiablity, infact, the 4306 can only provide stereo to zones 2 and 3 (also no zone 4 like the 5805) and all the amps in the 4306 are fixed with the acception of the 2 for channels 6 and 7 or stereo for zone 2. the power output from the 5805 is slightly better than the 4306 but not too noticable unless you are dealing with "very picky" speakers. I have Thiel CS3.6s (with impedences down to 2.6ohms) and they crank up just fine on the 4306.
5805 negatives:
the no OSD over HDMI/DVI really sucks but is to be fixed in the $1000 upgrade soon coming.
the disabled ethernet port (it does work for system updates) but not for internet radio or windows media yet, that sucks.
the shear size could be a negative but i personally find it to be a positive.
4306 negatives:
no real flexiablity, i wanted to add a 5 channel amp for my main room and use the 4306s amps to run 2 or 3 additional stereo rooms, this DOES NOT WORK!
NO iLINK inputs! come on Denon! how do you leave this off! sure Denon Link is great but i do not want a 3910 ($2500 DVD player) or 5910. you make a "receiver of the future" and leave me stranded with analog audio for my multichannel sources! this is unacceptable.
kinda cheap binding posts in the rear and an overall feel of "cheapness" compared to the 5805. very heavy on one side with no weight to speak of on the other.
Well, thats enough for now. My opinion, wait for the 5805 to become available with the updates. (sending it is a real pain in the *** at 100+lbs!). it is far superior to the 4306 and once they add the features it should have had (and did, they just were disabled) to begin with, this is the way to go.
