These two players, Marantz and Denon, are very similar, they use the same chipsets; and may even be clones of each other. I am not sure what differences (if any) there are. All I can say is, IMO it is crazy to spend $2,000 on a player that is already obsolete. These players both have Profile 1.1 (which is called Bonus view), not the latest 2.0 (BD Live) specification. On the plus side, they decode (and also bitstream) most audio formats and have 7.1 analog outputs. The realta post processor should theoretically improve video performance, though at least one user on this forum has expressed disappointment: http://www.avrevforum.com/showthread.php?t=2264&page=2
I personally have not used either one.