It makes sense comparing Marantz NR1510 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 NR1510 has 5.2 versus 2.0 for Onkyo TX-8020. Regarding power, then NR1510 has such a W/Ohm ratio - 50/8, 60/6 when TX-8020 has a power of 90/6. The THD is 0.08% for the NR1510 but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for NR1510 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. Only the NR1510 has Bluetooth support. The Marantz NR1510 has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Only the NR1510 supports Spotify. Only the NR1510 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 NR1510. Only the NR1510 supports HDMI Audio Return Channel (ARC). The HDMI eARC is available only on the NR1510. Of the two receivers in our comparison, HDMI CEC is present in only the NR1510. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the NR1510. The setup assistant will help you configure Marantz NR1510.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.