It makes sense comparing Sony STR-DH790 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-DH790 has 7.2 versus 2.0 for Onkyo TX-8020. And as for power, it is the same and equal to 90/6. The THD is 0.09% for the STR-DH790 but 0.03% for the TX-8020.
Competitors' digital to analog converter (DAC) is identical to 192 KHz/24-bit. Only the STR-DH790 supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Both models do not have WI-FI support. Only the STR-DH790 has Bluetooth support. Competitors do not have built-in Spotify service. Only the STR-DH790 provides HDMI signal transmission in standby mode. Both competitors are not able to scale the HDMI signal. Dolby Vision technology found support only on the STR-DH790. Only the STR-DH790 supports HDMI Audio Return Channel (ARC). The HDMI eARC is available only on the STR-DH790. Of the two receivers in our comparison, HDMI CEC is present in only the STR-DH790. The TX-8020 has a built-in phono stage for connecting a vinyl player. A voice control is not available. An ECO mode is not present in each of the AV receivers. The setup assistant will help you configure Sony STR-DH790.
Only the STR-DH790 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the STR-DH790.
The Sony STR-DH790 is better receiver in this comparison. Check Sony STR-DH790 price