The onkyo started at about a grand a year ago so was twice the price of the Sony. A different level of receiver. To many the inclusion of XT32 room correction would clinch the deal straight away. But there is no airplay on the onk nor gapless music streaming which is why I lost interest in this amp. I've been looking around to replace my Denon and both these amps crossed my mind but I've settled on a Yamaha 2020 now they have been discounted and that is levels above the Sony and the onkyo.
Anthem 710 : Oppo 103D : Apex A40 (5) : Seismic 110 : Panasonic 65VT65
where i live the onkyo is still more than twice the price of the Sony - if i had the choice that you are facing i would definitely go for the onkyo - but since i could not afford the onkyo i actually replaced my Pioneer VSX922 with the Sony
if i am able to sell my Denon PMA2000AE stereo integrated, i will probably get one of the old stock 818's as my main zone amplifier and leave the sony as my second zone amplifier in the network that im running
the main thing for me is that the onkyo could potentially work as an 11.2 processor with the addition of some power amps so im looking at either that or the Denon AVR-X4000 - im not too stressed over the streaming or media playback functionality since in the network i have enough alternative sources of both music and movies so i will rely on getting most of those from my server