It makes sense comparing Onkyo TX-SR353 vs Denon AVR-X2300W because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Onkyo TX-SR353 has 5.1 versus 7.2 for Denon AVR-X2300W. Regarding power, then TX-SR353 has such a W/Ohm ratio - 140/6 when AVR-X2300W has a power of 95/8, 125/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/24-bit for TX-SR353 and Burr-Brown 192 KHz/24-bit for the AVR-X2300W. Only the AVR-X2300W supports Bi-amping feature. The Denon AVR-X2300W can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Only the Denon AVR-X2300W can connect to the Internet via WI-FI. Rivals from our review have Bluetooth support. Only the AVR-X2300W supports Spotify.
Only the Denon AVR-X2300W has support for High dynamic range (HDR). HDMI signal transmission in standby mode is implemented in each of the devices. The AVR-X2300W can scale the input HDMI signal, unlike the TX-SR353. The HDR standard - Dolby Vision is not supported by these receivers.
The Onkyo TX-SR353 has 4/1 HDMI inputs/outputs versus 8/2 HDMI connectors of the Denon AVR-X2300W. 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. Receivers do not have a built-in phono stage for connecting a vinyl player. A voice control is not available. An ECO mode is only available for the AVR-X2300W. The setup assistant will help you configure Denon AVR-X2300W.
Only the AVR-X2300W has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the AVR-X2300W.