It makes sense comparing Marantz NR1510 vs Denon AVR-S950H 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 7.2 for Denon AVR-S950H. Regarding power, then NR1510 has such a W/Ohm ratio - 50/8, 60/6 when AVR-S950H has a power of 90/8, 125/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for NR1510 and AKM 192 KHz/32-bit for the AVR-S950H. 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. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay, AirPlay 2. Spotify can be used on each receiver. The NR1510 can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, and the AVR-S950H can receive a content from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, Mood Mix.
Both AV receivers support HDR10 technology (High dynamic range). 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. The AVR-S950H can scale the input HDMI signal, unlike the NR1510. The HDR standard - Dolby Vision is supported by these receivers.
The Marantz NR1510 has 8/1 HDMI inputs/outputs versus 8/2 HDMI connectors of the Denon AVR-S950H. The HDMI Audio Return Channel (ARC) feature supports both devices. HDMI eARC is available in each model. 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 2.3. These compared receivers have a built-in phono stage for connecting a vinyl player. Supported voice control technologies are identical - Amazon Alexa, Google Assistant, Siri, Josh.AI. It is also worth noting that the ECO mode is presented in each of the receivers. Both NR1510 and AVR-S950H can be configured using the Setup assistant.
Only the AVR-S950H has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the AVR-S950H.