Just looking at the first page of the 8801 thread shows quite a lot of differences. DAC's 32/192 dedicated to each channel better then the Denon 24/96 and up, HDAM on each channel, Troidal trans power supply bigger and better than in the Denon with amps., copper insulation 11.2 VS. 9.2, More processing power, XLR's.
If none of this matters to you, don't waste your money on the Marantz.
Lot more than that, if you are not interested in reading even the first page of the 8801 thread, buy the Denon and enjoy it. Also the 8801 is a significant upgrade over the 7005. I had one for 3 years and there is no way I would ever step down so far.
Life is enjoyable with good quality