The Onkyo is a good receiver, but I think the Denon operates speakers down to 4 ohm whereas the Onkyo doesn't. Not 100% sure though. You will get pass through, and TrueDolby HD which I think sounds better than Digital Dolby.
Television: Mitsubishi WD65737 DLP
Processor: Emotiva UMC-200
Amps: Carver AV 806x/Behringer EP4000
Mains: DCM TimeFrame 600 Center: AT 453C
Surrounds: AT 251.1 Sub: Danley DTS-10
Blu Ray: Panasonic DMP-BD655