It makes sense comparing Marantz NR1200 vs Onkyo TX-8020 because they both are able to give some premium features.
Considered AV receivers have the same number of channels 2.0. Regarding power, then NR1200 has such a W/Ohm ratio - 75/8, 100/6 when TX-8020 has a power of 90/6. The THD is 0.08% for the NR1200 but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for NR1200 and 192 KHz/24-bit for the TX-8020. None of the models support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. None of the competitors supports Auto speaker calibration. Only the NR1200 has Bluetooth support. The Marantz NR1200 has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Only the NR1200 supports Spotify. Only the NR1200 provides HDMI signal transmission in standby mode. Both competitors are not able to scale the HDMI signal. The HDR standard - Dolby Vision is not supported by these receivers. Only the NR1200 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 NR1200. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the NR1200. The setup assistant will help you configure Marantz NR1200.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.