I am looking for a receiver that does both Audyssey DSX upmixing (for older 5.1 movies) and modern Atmos \ DTS-X decoding, but it seems like I'm limited to just a handful of mid-2010s models from Marantz and Denon during the transition period. Am I missing something? Yes, I realise I'm chasing...
The Denon AVR-X1xxx series will do everything you need on a budget. I bought an AVR-X1300 for $300 new a few years ago and it is impressive, supporting 7.1 or 5.1.2 (Atmos), depending on what floats your boat.
Yamaha lets you display what you want on the front panel - either the decoder mode (e.g. Dolby Digital) or DSP mode (e.g. Sci-Fi) - press the Info button. If you enable Straight mode (Straight button on the remote), then no decoding nor DSP applies, so "STRAIGHT" is displayed.
I'm a Sony convert! Just bought my first Sony receiver yesterday, adding to my Sony TV and Blu-Ray player setup. Mainly, I just wanted to hear how well their DCS processing sounds. I've owned Harman\Kardon, Denon, Onkyo, and Yamaha receivers through the years.