It makes sense comparing Pioneer VSX-LX303 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, Pioneer VSX-LX303 has 9.2 versus 2.0 for Onkyo TX-8020. Regarding power, then VSX-LX303 has such a W/Ohm ratio - 100/8, 200/6 when TX-8020 has a power of 90/6. The THD is 0.08% for the VSX-LX303 but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for VSX-LX303 and 192 KHz/24-bit for the TX-8020. Only the VSX-LX303 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 VSX-LX303 has Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay. Only the VSX-LX303 supports Spotify. Only the VSX-LX303 provides HDMI signal transmission in standby mode. The VSX-LX303 can scale the input HDMI signal, unlike the TX-8020. Dolby Vision technology found support only on the VSX-LX303. Only the VSX-LX303 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 VSX-LX303. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is not present in each of the AV receivers. The setup assistant will help you configure Pioneer VSX-LX303.
Only the VSX-LX303 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the VSX-LX303.
The Pioneer VSX-LX303 is better receiver in this comparison. Check Pioneer VSX-LX303 price