It makes sense comparing Marantz NR1609 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, Marantz NR1609 has 7.2 versus 2.0 for Onkyo TX-8020. Regarding power, then NR1609 has such a W/Ohm ratio - 50/8, 70/6 when TX-8020 has a power of 90/6. The THD is 0.08% for the NR1609 but 0.03% for the TX-8020.
Competitors' digital to analog converter (DAC) is identical to 192 KHz/24-bit. Only the NR1609 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 NR1609 has Bluetooth support. The Marantz NR1609 has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Only the NR1609 supports Spotify.
Only the Marantz NR1609 has support for High dynamic range (HDR). Only the NR1609 provides HDMI signal transmission in standby mode. The NR1609 can scale the input HDMI signal, unlike the TX-8020. Dolby Vision technology found support only on the NR1609. Only the NR1609 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 NR1609. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the NR1609. The setup assistant will help you configure Marantz NR1609.
Only the NR1609 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the NR1609.