It makes sense comparing Yamaha RX-V671 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, Yamaha RX-V671 has 7.1 versus 2.0 for Onkyo TX-8020. Regarding power, then RX-V671 has such a W/Ohm ratio - 90/8, 150/4 when TX-8020 has a power of 90/6. The THD is 0.09% for the RX-V671 but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 192 KHz/24-bit for RX-V671 and 192 KHz/24-bit for the TX-8020. Only the RX-V671 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 RX-V671 has Bluetooth support. Competitors do not have built-in Spotify service.
HDR is not available on each model. Only the RX-V671 provides HDMI signal transmission in standby mode. The RX-V671 can scale the input HDMI signal, unlike the TX-8020. The HDR standard - Dolby Vision is not supported by these receivers. Only the RX-V671 supports HDMI Audio Return Channel (ARC). Unfortunately, HDMI eARC is not available on monitored devices. Of the two receivers in our comparison, HDMI CEC is present in only the RX-V671. These compared receivers have 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. Unfortunately, the setup assistant is not available in each of the models.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.
The Yamaha RX-V671 is better receiver in this comparison. Check Yamaha RX-V671 price