It may surprise the average consumer, but one of the features found in higher-end AV equipment is not just more channels or watts, but control idempotentcy.
When doing home integrations in a past life, we would often choose high-end Denon/Marantz over similarly spec'd Onkyo/Pioneer units specifically for this reason.
Serial ports provided the ability to more robustly connect and get device feedback, which was huge. Also, discrete on/off and source selection were all but required for a fluid integration.
Imagine trying to keep a home integration system synced with the state of an AV receiver if all you have was an IR transmitter and some Source Up/Down commands. We attempted a couple of these and every time the client was so (understandably) disappointed that we started requiring pricier equipment models in order to make the system meet expectations.
When doing home integrations in a past life, we would often choose high-end Denon/Marantz over similarly spec'd Onkyo/Pioneer units specifically for this reason.
Serial ports provided the ability to more robustly connect and get device feedback, which was huge. Also, discrete on/off and source selection were all but required for a fluid integration.
Imagine trying to keep a home integration system synced with the state of an AV receiver if all you have was an IR transmitter and some Source Up/Down commands. We attempted a couple of these and every time the client was so (understandably) disappointed that we started requiring pricier equipment models in order to make the system meet expectations.