It makes sense comparing Sony STR-ZA810ES vs Onkyo TX-8020 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Sony STR-ZA810ES has 7.2 versus 2.0 for Onkyo TX-8020. Regarding power, then STR-ZA810ES has such a W/Ohm ratio - 100/8 when TX-8020 has a power of 90/6. The THD is 0.09% for the STR-ZA810ES but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, 384 KHz/32-bit for STR-ZA810ES and 192 KHz/24-bit for the TX-8020. Only the STR-ZA810ES supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Only the Sony STR-ZA810ES can connect to the Internet via WI-FI. Only the STR-ZA810ES has Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay. Only the STR-ZA810ES supports Spotify. Only the STR-ZA810ES provides HDMI signal transmission in standby mode. The STR-ZA810ES can scale the input HDMI signal, unlike the TX-8020. Dolby Vision technology found support only on the STR-ZA810ES. Only the STR-ZA810ES supports HDMI Audio Return Channel (ARC). The HDMI eARC is available only on the STR-ZA810ES. Of the two receivers in our comparison, HDMI CEC is present in only the STR-ZA810ES. The TX-8020 has a built-in phono stage for connecting a vinyl player. An ECO mode is not present in each of the AV receivers. The setup assistant will help you configure Sony STR-ZA810ES.
Only the STR-ZA810ES has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the STR-ZA810ES.
The Sony STR-ZA810ES is better receiver in this comparison. Check Sony STR-ZA810ES price