Onkyo TX-RZ710 vs Onkyo TX-NR626 comparison definitely makes sense.
Considered AV receivers have the same number of channels 7.2. Regarding power, then TX-RZ710 has such a W/Ohm ratio - 175/6 when TX-NR626 has a power of 160/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for TX-RZ710 and Burr-Brown 192 KHz/24-bit for the TX-NR626. Both the TX-RZ710 and the TX-NR626 support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay. Spotify can be used on each receiver. The TX-RZ710 can work with the audio stream from Deezer, TIDAL, Pandora, Tunein Radio, and the TX-NR626 can receive a content from TuneIn Radio, Last.fm, AUPEO, Simfy.
Only the Onkyo TX-RZ710 has support for High dynamic range (HDR). Compared AV receivers retain the quality of 4K/60Hz signal when transmitting from a source to a TV or projector. HDMI signal transmission in standby mode is implemented in each of the devices. Both rivals can scale the resolution of the incoming HDMI signal. The HDR standard - Dolby Vision is not supported by these receivers.
The Onkyo TX-RZ710 has 8/2 HDMI inputs/outputs versus 6/2 HDMI connectors of the Onkyo TX-NR626. The HDMI Audio Return Channel (ARC) feature supports both devices. Unfortunately, HDMI eARC is not available on monitored devices. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. Both models support the standard HDCP 2.2. These compared receivers have a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. A voice control is not available. An ECO mode is only available for the TX-RZ710. Unfortunately, the setup assistant is not available in each of the models.
Only the TX-RZ710 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-RZ710.