Im looking to take my home theater to the next level. Currently I have a Yamaha RX-V 1400 reciever and I am considering either a Denon 5805 or a 4806. Both seem to be very similar in features and performance. Is there anything about the 5805 that would make it a absolute must over the 4806 and justify the $2000 difference? Which would you choose if given the choice and why?

More info:
Currently I have a typical living room theater with a 62 inch Toshiba DLP, M60's, two VP 150's for centers, QS-8 surrounds, an M3 for rear, an SVS 20-39 and a Denon 2910 DVD, however I am working on a dedicated theater room and plan to switch to a front projector with a 104 inch screen.

Thank you for your input