I don't have either yet, but I have a 1930ci on the way.... I think this will boil down to how you like the sound of either... the denon with the burr brown 1738 dacs or the onkyo with the wolfson 8740 dacs... other considerations, the quality of the pre-amp section on the players, how big they are (if you have space limitations - the 1930 is so nice and slim).... my hd-a2 has the same wolfson dac as your onkyo, but only one, and I am about to go dual burr brown 1738 so I am interested to hear the comparison myself. I will let you know what I think when I have a chance to a/b test.
Listening: Outlaw Audio 950 | Pioneer Elite DV-47ai | 2x Marantz MA-700 + 2x MA-6100 | Energy RC-70 bi-amped + Outlaw Ultra-X12
HT: Pioneer Elite SC-71 AVR | LG 60PV450 plasma | all BIC 7 speaker surround + Klipsch sub-12hg | Sony BDP-S350 | WD TV